220 A. E. Verrill—Mollusca of the New England Coast. 
decidedly oblique and slightly elliptical, though somewhat more 
nearly circular than in the latter. The posterior portion is somewhat 
less tapered and has the terminal opening alittle larger. Its border, 
when perfect, is usually furnished with four shallow notches, the two 
nearest the dorsal side being somewhat larger than the others. The 
most marked distinction is in the more gently tapered form and in 
the absence of any distinct gibbosity or swelling at the widest 
portion, the decrease in size being very gradual toward both ends, 
while in C. Pandionis the widest portion forms a somewhat abrupt 
enlargement, often amounting to a slight rounded angle when seen 
in a dorsal view. This feature, with its smoothness, renders it some- 
what difficult to pick up fresh and moist specimens of the latter with 
forceps. Both species differ considerably in the amount of the cur- 
vature of the posterior part of the shell. 
One of our larger specimens is 11™" long; greatest diameter, 2°1™™; 
transverse diameter at the anterior end, 1°9 ; diameter at the posterior 
end °9™™. 
This species occurred at station 2048, in 547 fathoms, eight living 
specimens (No. 34,814); station 2092, in 197 fathoms, nine speci- 
mens (No. 38,122); and off Cape Hatteras, at station 2111, in 938 
fathoms, one specimen (No. 35,765); and station 2115, in 843 fathoms, 
thirty-six specimens (No. 35,628). 
This species is also closely related to a shallow-water species taken 
in abundance by the Albatross, off Cape Hatteras, in 14 to 48 
fathoms. The latter is, however, .a smaller species, with a more 
slender posterior portion and a perfectly circular aperture. 
Cadulus cylindratus Jeffreys. 
Jeffreys, Ann. Mag. Nat. Hist., February, 1877, p. 158; Proc. Zool. Soc. London, 
for 1882, p. 664, pl. 49, fig. 6. 
The few specimens referred to this species show some variation in 
form, some being decidedly curved, others only very slightly so. 
The shell tapers very slightly from the middle toward both ends, 
which are very nearly equal in size, circular, and scarcely contracted. 
The oral aperture is slightly oblique. The posterior opening, in our 
specimens, is finely and irregularly notched, probably accidentally. 
Length, 7°3""; greatest diameter, 1:‘7""; diameter of the oral end, 
1:-4™" posterior end the same. 
Station 2041, in 1608 fathoms, three specimens (No. 38,030). 
Off the coast of Europe, it was taken at several localities by the 
