But even now it is impossible to collect all known errors in this article for rectification. It is my view that the agnostids form a subclass, coequal in rank with Trilobita and other recognized subclasses of the Crustacea. Behind the eyes, the facial suture diverges rapidly to form posterolateral limbs that are greater than the width of the glabella at the nuchal ring.
As their width decreases gradually, this backward direction is achieved by the bending of the rear edge. They are typical in all respects, but due to compaction of the rock they are almost flat. The fixigens are practically confined to the palpebral lobes, as the facial suture cuts close to the dorsal furrow at the anterior end of the eye.
12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 101
The cranidium from Pioche, Nev., illustrated by Walcott, is not in the matrix of the pink Chisholm shale, but occurs in a yellowish micaceous sandy shale. The surface of the skull is covered with small papillae distributed in such a way that they are smaller, more numerous and more crowded. A cast of the pygidium, illustrated as Figure 3, is in the collections of the National Museum of the United States.
Further revision of the Asian species is necessary, but the foregoing will suffice for present purposes.
ATLANTIC PROVINCE SPECIES REFERRED TO DORYPYGE
20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. lOI .. Compared to D.richflwfcni, the Chihli species has a wider glabella, fewer granules and possibly wider fixigens. In the pygidium, the ribs, spines and axes are all more robust and the spines are curved backwards to a greater degree. We need only add that the Geological Survey of China has a number of undescribed forms at hand, so that the genus is represented by many species.
On the other hand, the Bornhohu species are closer to Dorypyge than to most of the British and New Brunswick ones. It is interesting to note that two undescribed species occur together in the Manuels Formation, southeastern Newfoundland. It is therefore clear that the large spines shift position, and that different spines receive the macropleural development in different species, just as it happens in Dorypyge.
Consequently, several species classified under Ptychoparia (Emmrichella) should be considered to belong to Emmrichella unless transferred to other genera due to misidentification. Hudson Valley, appear to represent a valid genus and thus represent a second genus of Lower Cambrian agnostids. lOI Archacaynostits priniigciiciis Kobayashi, Joiirn. Only in recent months has the existence of Etcraspis beyond Nevada been recognized.
Besides the Eureka district, it is now known from the Bloomington Formation in the Wasatch Mountains, from the Maryville of the Appalachians, and possibly from the Eldon of the Canadian Rockies.
EUPTYCHASPIS ULRICH, 1930 Euptychaspis minuta (Whitfield)
15 CAMBRIAN FOSSILS, 5TM CONTRIRUTION RESSER 23description, consequently they can be taken as characteristic of the species. Raymond's drawing of the genotype does not show the occipital spine and shows that the glabella is demarcated anteriorly. Elsewhere, Raymond states that the glabellais is not demarcated in front, despite the fact that his figure shows such a feature.
The latter rises above the level of the anterior part of the glabella and thus gives the genus its meaning. There is a significant resemblance to Lorensella Kobayashi, especially because of the large neck ring and cervical spine. However, faint traces of an anterior groove can be seen at the anterior corners, and the departure is therefore thought to be merely due to aging.
The cranidium has a straight anterior outline and the glabella is marked with the usual furrows. Recently, Kobayashi gave this species a new generic assignment, which was unnecessary, as will be discussed below. Hitherto observers have failed to note that the specimens from Wisconsin are internal casts, and consequently do not have the true appearance of their genera, as this method of preservation invariably increases the furrows.
In the pygidium, the characteristic feature of the species is found in the six broad, rapidly tapering marginal spines. In the illustrated holotype, the raised central portion of the rim has been entrained by the matrix.
NO. 15 CAMBRIAN FOSSILS, 5TH CONTRIBUTION RESSER 29 Manchuriella impar (Walcott)
The pygidium has two slender lateral spines curved downwards that emerge from the second segment of the pleural lobe of the pygidium. On the other hand, examination of the bibliographical references, the locality and the plate descriptions raises serious problems. The locality description leads to the assumption that the type species comes from Shantung.
This is a natural inference because the words "also found in Chihli" are used to introduce the citation of the second locality. However, in the plate description, the first living specimens from Shantung are called "cotypes", and the remaining two (figs, yi, j) from Chihli, "types of Ceratopyge orientalis Grabau". From the bibliographic citations it is evident that Sun considered the pygid to be his. 15 CAMISRIAN FOSSILS, 5TII RESEARCH CONTRIBUTION 3I of the revised description of Mansnyia says: "This genus was founded by me, based on some pygidia of the type Ceratopyge and some associated cranidia, which are not now referable to another distinct genus Taishania. " Therefore, it is clear that Mansuyia rests.
Recent study of the species of Coosia grouped for the recognition of a new genus for a number of trilobites, clearly related to Coosia, but which do not fit into described genera. A new diagnosis of Maryvillia should be written to give greater emphasis to the cranidial characters and to those of the pygidium now assigned to the genus. Anterior facial suture diverges slightly, and the back of the eye develops posterolateral limbs approximately equal in size to the fixigens.
The fusion almost eliminated the axial furrows and, on test, almost all the pleural grooves and furrows except the anterior pair. An undescribed pygidium associated with an illustrated cranidium was selected as representative of the species, and the pygidium was originally designated M.
NO. 15 CAMBRIAN FOSSILS, 5TTI CONTRIBUTION RESSER 33 Valid species of MaryviJIia include
This species belongs to the group that bridges the gap between Olenoides and Kootenia, a condition caused by the degree of pygidial fusion. Middle Cambrian, Ptarmigan; (loc. 63b) east base of Ptarmigan Peak, 6 miles E of Lake Louise, Alberta. Walcott noted the fact that this form has six joygidial spines and considered it a doubtful example of 0.
Its cross-section has low convexity, rather flat on top and with a slight keel projection. Fixigenes at the anterior end of the eyes reduced to Httle more than the width of the eye band. The outer surface appears to be smooth, but large exfoliated specimens have anastomosing lines on the pre-glabellar area that become strongest towards the anterior angles.
Likewise in the ocular platforms of librarians, similar lines radiate from the eyes. The pygidium has a high shaft and gently convex pleural lobes, in which both pleural furrows and furrows are clearly shown.
38 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 101
The presence of the lip places the species in Phylactents rather than Pseudosaltcria. loc. iic) quarry in Newton, Essex County, New Jersey. There is one or more smaller species in the Franconia Sandstone (Devil's Lake), and these forms resemble the small one to which Whitfield erroneously applied the name barabuensis. Neither the cranidium nor the pygidium has as great a convexity as the almost equally large P.
Only the anterior half of a cranidium has been placed in the collections at hand from the vicinity of the type locality. This cranium has large prominent palpebral lobes which gain their prominence mainly from the elevation of their posterior extremities. PNgitliuui is well represented by both the Winchell lectotype and the specimens in the National Museum.
If the outer surface of the test or an impression of it had been preserved, the trilobite would appear much smoother and with almost no furrows. Upper Cambrian, Franconia (Devils Lake) ; (loc. 8i) i mile northeast of Devils Lake; and \ mile southeast of Woods Quarry, Baraboo, Wisconsin. It is in the libranges that the greatest distinction is found when this species is compared with either P
In this case, the libragen forms almost a quarter circle, so it is shorter than the others. The pygidium is normal, with a rather rapidly tapering axis extending about two-thirds of the length of the pygidium.
NO. 15 CAMBRIAN FOSSILS, 5TH CONTRIBUTION RESSER 4I
The description of the species is therefore based on the pygidium, while Winchell's librarians simply refer to it. The pleural platforms are small, anteriorly equal about the width of the shaft, but tapering to extinction before the end of the shaft. Middle Cambrian, Changhia; northern slopes of Taishan, south of Tsi-nan-fu, Shantung, China.
Middle Cambrian, Changhia; (loc. C5) 3 miles south-west of Yenchuang; (loc. C52) 3 miles NE of Sintai, Shantung, China. Punctuation occurs most often when the fossil is an impression of the underside of the test. All specimens of Qiiadraticephalus in our collections show spots only when the outer layers of the testa are peeled off.
Although the pygidium is incomplete, so the length of the spines cannot be determined, it appears that the pleura is quite heavy. As now formed, this species is typical of the genus with a simple lip construction, libragen with large ocular platforms, and pygidium with a stout shaft. It is further characterized by the anterior subdivision of the pleura extending beyond the pleural plateau.
The axis is just over half the length of the tail and has a sharp postaxial edge that extends almost to the trailing edge. The pleural platforms are small triangular things that do not reach the back of the axis. The broad, slightly concave margin is almost smooth, except that the anterior subdivision of the pleura, as it broadens, remains visible almost to the lateral margin.
On the other hand, the posterior pleural subdivision pinches out at the foot of the rather steep slope from the pleural platforms.
BIBLIOGRAPHY
Pygidium characteristic of the genus with a large, stout, highly convex axis, extending almost the full length of the pygidium and terminating in a short postaxial ridge.
