GASTEROPODA PECTIXIBRANCHIATA. 
63 
ranged on the roof of the cavity, and its filaments are frequently very 
long. 
Capull's, Monlf. — Pileopsis, Lam. 
A conical shell with a recurved and spiral summit, which has long 
caused it to be placed among the Patellge; the lu'anchiEe are in one 
range under the interior margin of the branchial cavity; the pro- 
boscis is long, and there is a closely plaited membranous veil under 
the neck; the eyes are at the external base of the conical tentacula* * * § . 
The 
ITipponyx, Defr. 
Would appear from the shell to be a fossil Capulus, very remark- 
able, hoAvever, for a bed formed of calcareous matter, on which it 
rests, and which probably exuded from the foot of the animalf. 
Crepidula, Lam. 
The shell oval, Avith an obtuse horizontal point, directed obliquely 
backwards and laterally; the aperture forming the base of the shell, 
Avhicli is half closed beneath and behind by a horizontal plate. The 
abdominal sac which contains the Auscera is on this plate, the foot 
beneath, and the head and branchiae foinvards. The latter consist of 
a range of long filaments attached under the anterior margin of the 
branchial caAuty. The eyes are at the external base of tAVO conical 
tentacula The genus 
PiLEOLus, Sowerby, 
Appears to consist of Crepidulae, in Avhich the transA^erse plate occu- 
pies half the aperture; their shell, hoAA'cver, is more like that of a 
Patella §. They are only found fossil. 
Septaria, PeV.— N avicella, Lam. — Cimber, Montf.,^^. 
The shell resembles a Crepidula, except that the summit is symme- 
trical and laid on the posterior margin, and that the horizontal plate is 
less salient. The animal is also provided Avith an additional, irre- 
gularly shaped, testaceous plate, horizontally connected Avith the 
superior surface of the muscular disk of its foot, and covered by the 
abdominal sac, Avhich it partially supports. It is probably analogous 
to an opererdum, but does not exercise its functions, being, in a 
measure, situated internally. The animal has long tentacula, at 
* Patella hungarka, List., 544 — 32; — Put. cuhjpira, Chemn., X, clxix, 1C43 — 
44 ; — Pat. mitrula, Gm., List., cxliA% 31. 
-f- Patella connicopice, Lam., Knorr., Petrif., II, part ii, pi. 131, f. 3, and Blainv., 
Malac. 
+ Patella foryiicata, 'List. 5-15, 33, 35 •, — P. aculeat a, Chemn., X, clxviii, 1624 — 
25 ; — P. Goreensis, Martini, I, xiii, 131, 132 ; — P. solea, Naturf., XVIII, ii, 15 ; 
— P. crepidula, Adans. Seneg., I, ii, 9 ; — P . porcellana. List., 545, 34. 
§ Pileolus jdicatus, Sowerb. ; — Pil. laris. Id., Genera of Shells, No, IX ; — Pit. 
nentokles, Desh., Ann. des Sc. Nat., I, xiii, 3, a, h, c. 
