THE NAUTILUS. 9 
Ischnochiton elizabethensis, n. sp. 
Shell small, elliptical-oblong, elevated at an angle of about 105° ; 
carinated, the side-slopes somewhat convex. Color whitish or buff- 
ish-olive, finely and closely mottled all over with light olive-green, 
or having angular patches of olive at the sides of each valve ; some- 
times with black-green triangles on the ridge of some valves (valves 
ii, iv, vil, vili); the posterior margins of valves more or less tessel- 
lated light and dark. Girdle indistinctly tessellated with numerous 
small green bars or patches. 
Intermediate valves not beaked. Valves finely granulated 
throughout, the sculpture closely resembling that of Trachydermon 
cinereus L. Lateral areas slightly raised. Posterior valve having 
the central mucro somewhat prominent, posterior slope concave. 
Interior bluish, with a pair of darker green rays in each inter- 
mediate valve; the inflected posterior margin tessellated. Sutural 
plates small, separated by a very wide, straight, smooth sinus. An- 
terior valve having 10, intermediate valves 1-1, posterior valve 11 
slits; teeth smooth and sharp; slit-rays showing as whitish lines; 
posterior tooth in intermediate valves short, removed from the pos- 
terior margin of valve by about its own length. Eaves narrow. 
Girdle densely clothed with smooth, flattened imbricating scales. 
Length 103, breadth 7 mm. 
Habitat: Port Elizabeth, S. Africa. 
This little species closely resembles Trachydermon cinereus L. 
(marginatus auct.), or dentiens Gld., in sculpture and coloration, 
but differs from them in the totally diverse girdle-covering. I am 
indebted to Mr. G. B. Sowerby for specimens. It is the Ch. mar- 
ginatus of his useful “ Marine Shells of S. Africa,” p. 50. 
NOTICES OF NEW JAPANESE MOLLUSKS, II. 
BY H. A. PIESBRY- 
Siphonaria sirius n. sp. 
Shell oblong, polygonal, low-conical with subcentral, erect, apex ; 
primary ribs all single, generally 7, strongly elevated and white ; inter- 
spaces wide, dark brown, radially finely ribbed. Interior brown- 
black, the larger ribs indicated by white rays; Siphon occupying a 
single rib, never a double one. Cavity with a white callus (rarely 
