87 
irregular imbricating scales, which are finely striated. 
Measurement.— Length, 26 mm.; breadth, 7 mm. 
Habitat. —St. Vincent’s Gulf ; dredged by Dr. Verco. 
emarks.—This species is much broader in proportion to its 
length than juloides, the first valve being the broadest and very 
and Pilsbryanus by the anterior valve being longitudinally much 
Shorter, the creamy white colour, and the densely irregularly 
Scaled girdle. I am indebted to Dr. Verco for specimens of this 
and the following species. 
Callochiton rufus, sp. nov. Pl. i., figs. 2a—g. 
the lateral area of valve seven, which is pure white; from this 
valve a white line traverses the girdle; also the four first valves 
have a light spot on the posterior margin. 
Anterior Valve, — Under pocket lense quite smooth, with the 
exception of a few concentric growth lines. Megalospores are very 
distinct under compound microscope. Slits 11, teeth crenulate, 
which appearance is caused by the slight projection of the props. 
The spongy character of the eaves is continued in the slits 
between the teeth. 
Posterior Valve is almost equally divided into two areas, the 
orsal or central broadly wedge-shaped, traversed by eight 
longitudinal strongly raised ribs, similar to those of the pleural 
areas of the median valves. Mucro median, although shallow, 
decidedly more prominent than in C. platessa. Posterior area 
smooth, decidedly raised at the junction with the dorsal area. 
Slight concentric growth lines are discernible. 
Median Valves.—Lateral area much raised, slight ‚growth 
The pits between are very deep where they join the lateral area. 
Dorsal area is raised, wedge-shape, divided from the pleural area 
by a deep spindle-shaped pit, tapering off into a curved groove at 
