GASTEROPODA PECTINIBRAXCHIATA. 
59 
A small species, the Trochus tesselatus, L. ; Adans., Senefj., 
XII, 1 ; List., 642, 33, 34, -with a brown shell spotted with 
whitish, is very abundant on the coast of France* * * § . 
Phasiaxella, Laju . 
An oblong or pointed shell, similar to that of several Bulimi and 
Lymnaete; the aperture also higher than it is wide, and furnished 
with a strong operculum ; base of the columella sensibly flattened, 
but no umbilicus. 
They inhabit the Indian Ocean, and are much sought for by col- 
lectors on account of the beauty of their colours. The animal is 
provided with two long tentacula, with eyes placed on two tubercles 
at their external base, and with double lips that are emarginated and 
fringed, as well as the wings, each of which has three filaments f. 
Ampulla R i A, Lean. 
A round, ventricose shell, with a short spire, as in most of the He- 
lices; the aperture higher than it is wide, and provided with an oper- 
culum ; the columella umbilicated. 
They inhabit the fresh or brackish waters of hot countries. The 
animal has long tentacida, and eyes placed on pedicles at their base. 
In the roof of the respiratory cavity, by the side of a Itranchial comb, 
according to the observations of Messrs. Quoy and Gaymard, is a 
large pouch, without an issue, that is filled Avith air, and which may 
be considered as a natatory bladder;]:. 
The Lanist^e, Montf., are Ampullariee, with a large, spiral, con- 
A'oluted umbilicus §. 
Helicina, Lam.\\ 
Judging by the shell, the Helicinee are Ampullaria? in Avhich the 
margin of the aperture is reflected^. 
^\nien this reflected margin is trenchant, they are the AmpiiUince , 
Blainv. ; and Avhen it is in an obtuse ridge, the Ohjgir(p, Say. 
* Add, Trochus labeo, Adans., Seneg., XTI, List., 68, 442; Troch. Pharuonius, 
List., 637, 25 ; — Tr. rusticus, Chemn., V, clxx, 1645, 46; — Tr. nitjerrimus, lb. 47 ; 
— Tr. cctjtjplius, Id., clxxi, 1663, 4; — Tr. viridulus, Ib. 1677; — Tr. carneus, Ib. 
1682 ; — Tr. tilbidus, Born., XI, 19, 20 ; — Tr. asper, Chemn., Ib., cLwi, 1582 ; — Tr. 
citrinus, Knorr., Del., I, x, 7; — Tr. granatum, Chemn., V, clxx, 1654 — 55 ; Tr. 
crocatus, Born., XII, 11, 12; — Turbo atrafus, Chemn., V, clxxvi, 1754 — 55 ; — 
Tu7-bo denfatus, Id., clxxviii, 1767, 8, &c. 
t Buccinuiii h-itonis, Chemn., IX, exx, 1035, 1036; — Helix solid a, Born., XIII, 
18, 19. 
+ Helix ampidlacea, L., List., 130 ; — Bulimus urceus, Brug., List., 125, 26. 
§ Ampulla carinula, Oliv., Voy. en Turq., pi. xxxi, f. 7, copied Blainv., Malac., 
xxxiv, 3. 
II Montfort has changed the name Helicina into Pifonvilla, but it has not been 
adopted, and can only be quoted as a synonyme. 
^ The Hel striata, Blainv., Malac., xxxv, iv. 
