Descriptions of new species of shells from California in the collections of the National Museum

46 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM.

Body

rinj?s, 1

+

^{10. Caudal rings, 37. Tubercles of body and tail}

oloDgated, slightlyrecurved, usually prolonged into slender filaments;

those on the 2d, 4th,

and

Gth body rings

much

largerthan theothers;

tubercles prominent

and

filamentoseupon the4th, Gth, 9th,12th, IGth,

nud

20th caudal rings. Ventral tubercles

upon

Gth,7th, 8th,

and

9th bodyrings. Occipital crest very high, with live prominent tubercles, the anterior twowith long filaments. Length of snout equal to dis- tancefromposteriormarginoforbittogill-opening. Operculum

marked

with fine, radiatingstrine.

Radial formula.

—

^D. 19(the firstimperfect). P. 18. V.4.

Color.

—

Yellowish-brown; the eyesand cheeks covered withradiating,

wavy

lines of light brown. Snout encircledby a narrow, undulating, whiteband nearits middle.

The

Commission has an accurate sketch by Mr. Emertou.

April30, 1878.

»ESCKIB>TIO.>'.«(

OF NEU'

SPECIE!^

OF

MHEI.I.S FROITI

€Ar.IFORNIA

i.\ Tin; coi.i-iErTio:v.s

of the

natsoivai. miseijiII.

By W.

II.

OALL.

Haliotis (.'var.) assimilis, u.s.

Shell solid, strong,not very thick, with a rather light piuk,white

and

greenish nacre, usuallywith five open holes_; spire

more

elevated than that of any other Californiau species,consisting of two and ahalf or three whorls; aperture very oblique in adult specimens, the thickened margin of the columella narrow,

somewhat

concave, inclined sharply inward and upward, aboutthree-fourths aslong asthe columellar side, of the aperture.

Between

therowofopenings

and

the columellaredge, the space isunusually broad,

marked midway by

an obtusecarina, sep- arated from the

row

of holes

by

ashallow channel; surfacereddish or dull greenish, with rather rough, crowded, unequal, spiral ribs

and

rounded, irregular, wavy, radiating undulations crossing the spiral sculptureobliquely.

The

muscular impression, in most specimens, is

but lightly marked, and, exceptforoccasional spot-like impressions, is

smoothly nacreous, like the rest of the interior. Lon. 4.5 in. Lat. 3.0 in. Alt. of spire 1.5 to 2.0 in. Aperture3 inches wide and 3.75 long, inan adult specimen.

Hah

i

tat—

Monterey; S3H Diego, Ciil.; in deep water only; thrown up by heavystorms, usuallydead and worn

when

found and everywhere

rare. Mus. Cat. 31267.

This species, or variety, has long been

knowu

to

me

and to most Californiau collections, but has not hitherto been characterized,owing

fo thedead condition of most of the specimens found. Mr. Hemphill having forwarded two freshspecimens,it seemswell toputit on record.

The

form is different from any other Californiau species; the spiral

PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 47

sculptureis that of II. rv/cscens; the radiating sculpture,except thatit isnot sharp orimbricated,recallsILcorrugatus,

and

the nacre issimilar but less bright. These characters suggest the possibilityof its being a hybrid betweenII. corriigatusand riifescens;butifthis be thecase,

why

shouldit nothave a similarhabitat? Those

two

species arelitto- ral, but this is exclusively deep-water. I have received it from Dr.

Oanfield, Mrs. Capt.Lambert,and others, in pastyears, and have exam- ined

some

twenty specimens of all ages.

Acmasa (scabravar.?) Morchii, n.s.

Shell conical,

much

elevated, with asub-centralrecurved apex resem- blingthatofHelcionpectinatuscovered withclose-set,rough, imbricated ribsandriblets, thecoarse, imbricated, sharp lines of growth forming with the other sculpture aclose reticulationinsomespecimens. Interior with a brown-mottled spectrum

and

margin, otherwise white; exterior dull grayish orgreenish speckled.

The

imbrications on the principal ribs very strong, in

some

specimens forming small spines concave beneath. Lat.IG""". Lou. 20""". Alt. ^10™'".

Tomales Bay,California, Ilemphill,16 specimens. Mus.Cat.31268.

This very peculiar form has the sculpture of A. scabra., but

much

exaggerated, and very nearly the profile of Helcion pectbiatus.

The

recurvedapexrecalls that of A. persona. It would not be referred to any described Californian species if itscharacters,as they appear, were the onlytest.

But

it isalmost certain that all the speciesof Limpets

and

Siphonaria', which have this peculiar elevated shape, acquire it

froma particularhabitatwhich they seem to prefer. This

may

be the stem ofalargeFucus, a shell, roundpebble, or

what

not, asin thecase of those species of

Acmaa

usually (but wrongly) termed Nacella by Californian conchologists: Acnucaosmi; Liriolasithspiralis; etc.

They

all havea flattenedor normalvariety, though thisisoften veryrare.

Hence

I consider the elevated form and pointed apexas probably due toapeculiar habitat, as ⁱⁿ the other cases; aview which is borne out

by

apeculiararcuation of the margin in most of thespecimens, as

if the creature

had

lived on aroundshell orpebble.

Eliminating the elevation as apermanentcharacter, the shell, appa- rentlyvery limited in itsdistribution, might well be a hybrid between

.1.scabra

and

A. persona.

Whether

thisbe the caseor not,itisa very remarkable form,

and

well deserves a name, even if only of varietal value.

We owe

its discoveryto Mr. Hemphill's industry and eminent

abilitiesas acollector.

Afril30,1878.