MUSEUM OF COMPARATIVE ZOOLOGY. 267 
416 fms., near Grenada, bottom temp. 42°.5 F.; and many stations of the 
U.S. Fish Commission off the coast of New England. 
The specimens are smaller, on the whole, and somewhat less rude, but other- 
wise do not differ from those from more northern stations. 
Genus CRYPTODON Torrton. 
Cryptodon orbiculatus Secuvrnza. 
Verticordia orbiculata Seguenza, Mon. Vert., p. 9, 1876. 
Axinus orbiculatus Jeffreys, P. Z. S., 1881, p. 703, pl. 1xi. fig. 5. 
A shell (one valve) which seems to agree with Seguenza’s description was 
dredged at Station 220, in 116 fms., near Santa Lucia, but I cannot make out 
such a sculpture as is figured by Jeffreys on the plate referred to. There are 
extremely fine radiating rows of dots, and a powdery surface over them, but I 
cannot make out riblets and pores such as are figured, 
Cryptodon flexuosus Monracu. 
One valve occurred at Station 262, in 92 fms., near Grenada. 
Cryptodon pyriformis, n. s. 
Cryptodon ? obesus Verrill, Dall, Bull. M. C. Z., IX. p. 186, 1881. 
Shell thin, white or flesh-color, subtranslucent, not very convex, when 
fresh with an appearance as of white dust on the exterior surface, beaks high, 
narrow, rather pointed, more or less recurved, with a depressed lanceolate 
lunule in front of them; anterior dorsal slope concave, steep, terminating 
about half-way between the umbo and the base in a rounded angle; posterior 
slope shorter, slightly convex, then inflexed to meet the posterior rib which 
has its steepest side posterior and anteriorly passes into a wider flexure of the 
surface which lies between the rib and the middle part of the shell; the base 
is rounded and produced in the middle line, the curve extending from the rib 
to the anterior angle; the outer surface is marked by faint lines of growth 
and obscure malleations; the interior is smooth, exhibiting the flexuosities; 
the hinge-line is narrow and flattened under the beaks, perfectly edentulous ; 
the muscular impression faint and elongated. Lon. 11.2, alt. 14.0, diam. 
6.5mm. A larger but imperfect specimen must have been 17.0 mm. high. 
Habitat. Yucatan Strait, 640 fms. (broken valves); also at the Fish Com- 
mission Stations 2646 and 2678, off the Florida and Carolina coasts, in 85 and 
731 fms. 
This fine species was doubtfully referred to C. obesus in my preliminary 
report. Since then I have had the opportunity of examining an unparal- 
leled series of this genus comprised in the Jeffreys collection, besides a good 
