CASTALIA.—P uate I. 
with one oblique groove, dorsal margin round, 
elevated; lateral margin excavated between the 
wing and the end of the angle; anterior side 
shorter; dorsal margin sloped; teeth thin, 
laminar. - 
SOWERBY. 
Hab. British Guayana. Schomberg. 
Species 4. (Mus. Brit.) 
CasTaLia ovaTa.—Cas. testa trigono-subquadratd, ele- 
vatd, crassa, pallidée olivaced, concentricé nigro- 
lineata, concentrice rugatd, prope umbones usque 
ad medium rugis magnis paucis radiatim diver- 
gentibus impressa ; latere postico acute angulato, 
ared postangulari trigond, depress ; latere antico 
brevi, declivi ; umbonibus elevatis, angulatis. 
THE OVATE CASTALIA. 
Shell subquadrately trigonal, 
elevated, thick, pale olive, with concentric black 
lines, concentrically wrinkled; near the umboes 
as far as the centre impressed with large, few, 
radiating divergent 
wrinkles; posterior side 
acutely angular; postangular area trigonal, de- | 
pressed; anterior side short, sloped; 
elevated, angular. 
D’Orsieny. MS. in Mus. D’Orb. 
Hab. Brazil. 
umboes | 
This species resembles Castalia retusa, but is more 
nearly square than oval. 

Species 5. (Mus. Hanley.) 
CastatiA Hantryana.—Cas. test tumidissimd, ponde- 
rosd, trigond, concentricé subrugosd, prope wmbones 
rugis paucis magnis medio convergentibus im- 
press ; latere postico elevatim obtuse angulato, 
area postangulari subcomplanato, margine dorsali 
depresso, laterali concavo,; latere antico brevi, 
margine dorsali declivi ; umbonibus magnis, pro- 
minentibus, angulatis. 
Hanvey’s Casrarta,—Shell very tumid, ponderous, 
trigonal, concentrically slightly wrinkled, impressed 
near the umboes with few large wrinkles con- 
verging in the middle; posterior side with an ele- 
vated obtuse angle; postangular area rather flat, 
with dorsal margin depressed, lateral margin con- 
cave; anterior side short, with dorsal margin 
sloped ; umboes large, prominent, angular. 
SoWERBY. 
Hab. 

(?) 
Less oblique and deeper from apex to ventral margin 
| than Castalia ambigua ; with the umbonal wrinkles 

larger and thicker. 

