EXPLANATION OF PLATES
U. S. NATIONAL MUSEUM BULLETIN 115
Plate (i.
DOLATOCRINUS ORNATIIS Meek
Fig. 1. Basal view of the typo, having small radial ridge. Columbia Uni- versity,
New
York.2. Tegmenofanotherspecimen, covered withsmalltubercles.
3. Basalviewoflargerspecimen, withoutanyradial ridge.
4. Lateralview ofsame,showing tubercleson tegmen,and projectinglip atthe edge.
Onondaga: Columbus, Ohio.
DOLATOCRINUS ASPERATUS Millerand Gurley
5, 6, 7. Basal, lateral, and tegmenal views of the type, showing radial ridgeformedofconnectednodes. UniversityofChicago,No.6071.
8.
A
largerspecimen, with large disconnected nodes and pitted surface ornament.9. Large specimenwithradialridge not well defined; coarsepustulesand smallnodesmoreor lessradiately arranged, tendingtoformgeomet- ricalfigures.
10. Large specimen with narrow radialridgelimited to primibrachs;fine striaeformingtriangles.
11. Lateral \'iew of specimen with continuous ridge extending to arms;
fine striateornament. TypeofD. marshi, var. hnmiltonensisV\'a.chs-
mutandSpringer.
12. Basalviewof similarspecimen, showingcontinuousridge.
Among these six specimens, all having the same general form and proportionsand10 arms,arefourdifferentkindsofradial ridge,and threestyles ofsurfaceornament.
Hamilton: Louisvillearea.
DOLATOCRINUS, species 16
13. The tegmen ofone ofthe few known specimens havingparts ofthe armsand pinnules attached; it isimbedded, and the dorsal parts partscannotbeseen.
Hamilton: Louisvillearea.
65
Plate 7.
Page.
DOLATOCRINUS GRANDISMillerand Gurley 32 Figs. 1,2, 3. Basal, lateral, and tegmenal views of a typical specimen with
the most frequent type of surface ornament. It showsthelarge pentagonal basal funnel; the large iBrj distally angular with two large fixed pinnulars leadingfrom IIBrj partlyrestinguponit; the positionandsuccessionofthe fixedpinnules leadingfromthe IIBr tothe openingsatthemarginofthetegmen betweenthe arms; also
how the large biserialarm, fora distance of two ormore biserial pairs ofossicles, isincorporatedinthe calyxwall.
4. Detailof aninterrayof largespecimen having12pinnule openings;
it showshow the openings are formed where the sutures leading from the tegmen ambulacra meet the grooves at the distal end of thefixedpinnules. X2.
5. Detailofanotherspecimen showingsuccessionofIIBr,and twobiserial pairsofbrachials, andthe courseofthefixedpinnules leading from
^ them.
6.
A
fractured cross section of the calyx, showingthe inverted conical pit halfthedepthofthecalyx, involvingbasalsandradials.7. Specimen\vithverysharp sculpturing,coarsewrinklesand anobtuse medianridge; alsothe basalpitwitha sectionofsteminposition.
8.
A
variant, with a more distinctly striate ornament;it hasin three interrays a truncate firstinterbrachial withanothersucceedingit,followedbytwolargepinnulars leadingfromIIBr,,andinthe other twothetwolargepinnularsresting directlyoniBr,,asusual inthe species.
AllOnondaga: Louisvillearea.
66
U. S. NATIONAL MUSEUM BULLETIN 115 PL. 7
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DOLATOCRINUS GRANDIS.
For explanation of plate see page 66.
U. S. NATIONAL MUSEUM
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BULLETIN 115 PL. 8
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DOLATOCRINUS SPINOSUS AND D. INSUETUS
FOR EXPLANAT.ON OP PUATE SEE PAGE67.
Plate 8.
DOLATOCRINUS SPINOSUS Millerand Gurley
Fig. 1. A'si^ecimenbelowaveragesize; basalview,showingstrongradialridge limitedto radialand IBr,andrather pittedornament.
2. Lateralviewofsame,showingstoutspinesonthetegmen,and pinnule openingsbetweenarmbases.
3.
A
veryyoungvariant,with disproportionally high tegmen,andridges extending to arms. Probably should be referred toD.insuetus—
fig. 8below.
4.
A
smallspecimenwithextremelyfine striateornament,and veryhigh knifelikeridgesonradialand IBr.5.
An
average specimen with typical striate ornament, and usual shape oflarge iBr; remainsofhighradialridgeslimitedtoIBr.6. Another specimen with variationin shape of the large iBr, which is nearlyacuminateinsteadofbroadly truncate.
7. Tegmenofthesame,showingthe broken-offbasesofstrongspines, the arrangementofplates,andposition ofpinnuleopenings.
DOLATOCRINUS INSUETUS Rowley
8. Basal view of specimen with perfect typical ornament, and showing theradial ridgesextendingtothe arms; the knifelike projectionsof theridge are brokenoff.
AllOnondaga: Louis\-illearea.
18:^.081—21 6 67
Plate 9.
Page.
DOLATOCRINUSMAJOR Wachsmuthand Springer 36 Fig. 1.
A maximum
specimen; basal view, showing basal plates nearlyresorljedbygrowth ofaxialcanal.
2.
A
minimumspecimen, \vith basalsinnormalcondition; nodeson IBr producedintospines.DOLATOCRINUS MULTIBRACHIATUS Rowley 38
3.
A
flattened specimen, \vith details of deUcate ornament ])roughtout byetching; verysharp thin ridges follow theradial seriesfrombase to arms, where 4arm openingsto the halfrayare seen, indicating about40 inall; innercore ofstemattached,onwhichthe peripheral flanges ofthe nodalsare mostly broken away.4. Lateralviewofanotherspecimen, showing8armstotheray.
DOLATOCRINUS GRANDISMiller and Gurley 17,32 5. Specimen withpitted sculpturing, ligured to showthe displaced por-
tions ofstemseeninthe basalpit,inwhichthe flanged nodals^\ith theirperipheral cogs, and someinternodals, are well exposed; and alsotheverylarge sizeoftheaxialcanalproximaltothe calyx.
AllOnondaga: LouisWllearea.
DOLATOCRINUS,species;fragmentsofcolumn 17,18 6. Transverseviewofstem fragmentat joint face, probably from toward
thedistalend, showingthe smallsize oftheaxial canal in that part compared with the proximal portion shown in the last figure.
7. 8. Twofragmentsshowingthe greatsizesometimesattained bythefin- like cogs, which here arch over 10 or 12internodals.
9,10, 11, 12, 13. Various fragments showingtherelation ofthe nodaland internodal cohimnals, in different stagesof development.
AllfromLouisvillearea: Probably Hamilton.
68
BU LLETIN 115 PL. 9 U. S. NATIONAL MUSEUM
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