231 
Length, 10 mm.; breadth. 6:25 mm.; thickness, 4 mm. 
Habitat.—Yankalilla Bay, in sludge, at 20 fathoms, many 
alive; Backstairs Passage, Port Lincoln, Eastern Cove, Kangaroo 
Island, at varying depths, several ( Verco). 
Types in my cabinet. 
Diagonsis.—Its nearest ally in our waters is C. scaphoides, 
Hinds, but the latter isa more obese shell, the transverse section 
is more uniformly convex, the anterior dorsal margin is compara- 
tively longer, the angle between the anterior and _ posterior 
margin is more obtuse, the left valve is not so included in the 
right posteriorly, the surface behind the umbonal ridge is not so 
wide, or so excavated, and so the ridge is not so valid. A nearer 
ally is C luteola, Carpenter, from San Diego Bay, which has the 
same compressed form, but in this species the anterior part of the 
shell is longer than the posterior, the junction between the 
anterior dorsal margin and the ventral is a larger curve, and the 
right valve does not include the left. 
Nore Upon Murrx Umaiuicatus, Ven.-Woods. Pl. vii., 
figs. 4, 4a, 4b, 4c. 
Adams's name scalaris has priority of Wood’s umbilicatus, but 
the former is pre-occupied by Brocchi for a fossil Murew, and is 
thus excluded. So Tryon proposed the name of I Angasi as a 
substitute for scalaris (Man. of Conch. Vol. IL., p. 109). He 
did not, however, know its identity with IL wmbilicatus. This 
latter name, therefore, has priority. The identity is vouched for 
by Brazier. He sent specimens of the shell to H. Adams, who 
said it was identical with that named I. scalaris by his brother, 
A. Adams (Proc. Linn. Soc. New South Wales, Vol. VIIL., 
Part I., p. 116). Sowerby, in Thes. Conch. Mon. Murex, p. 54, 
gives it in his alphabetical list as scalaris, Ad., Gen. Fusus ?, 
without description or plate, and does not notice it in his Mon 
Fusus. Tryon gives no plate of either scalaris or umbilicatus ; 
I have therefore had a figure of MZ. umbilicatus, Ten.-Woods, 
from St. Vincent Gulf, with its operculum executed. 


EXPLANATION OF PLATES. 
e Prats VI. 
ig. 
1, la. Tritonidea fusiformis, Verco. 
lb. Details of sculpture. 
2, Qa. Var. Adcocki, Verco. 
38, 8a, 3b. Harpa punctata, Verco. 
4, 4a. Voluta translucida, Verco. 
5, 5a. Phos tasmanica, J’en.- Woods. 
6. Triton (Argobuccinum) mimeticus, J’ate. 
et Operculum of Triton (Argobuccinum) mimeticus. 
Dentition of Triton (Argobuccinum) mimeticus. 
