EAST AMERICAN SCAPHOPOD MOLLUSKS. 



63 



to 20 primary riblets, narrower than the spaces they separate; these 

 are increased to double the original number, or more, all becoming 

 broader and flatter, thus reducing the intercostal spaces to mere 

 threads; finally, at about the beginning of the anterior third they fuse 

 into a smooth surface, in which every trace of sculpture is lost, save 

 for some irregular growth lines. The sculptural features are confined 

 to the outer shell layer, and, though superficial, are very noticeable 

 wherever the periostricum is intact. An apical notch as in the 

 typical subspecies is present, but is less deep. 

 Length, 82 mm.; diameter, 10 mm. (Verrill). 

 Length, 75 mm.; diameter, 9 mm. (Verrill). 

 Length, 96 mm.; diameter, 10 mm.; arc, 4.5 (off Chesapeake). 

 No single specimen seems to have been set apart by Verrill as a 

 type. A selected type, Cat. No. 34687, U.S.N.M., was dredged by 

 the Albatross at U. S. B. F. Station 2083, off Georges Banks, m 959 

 fathoms, gray mud, bottom temperature, 40° F. It measures- 

 length, 80 mm. ; diameter, 10 mm. 



A large series in the museum collection from off Block Island and 

 Nantucket to Hatteras in 843 to 1,813 fathoms is shown in the follow- 

 ing table: 



Remarks. 



Southeast of Georges Bank, U. S. B. F. Station 



2531 

 Off Georges Bank, U. S. B. F. Station 2077. - . 

 Off Georges Bank, U. S. B. F. Station 2083. . . 

 Off Georges Bank, U. S. B. F. Station 20/6... 

 Off Georges Bank, U. S. B. F. Station 2084. . . 

 Off Georges Bank, U. S. B. F. Station 2570 . . . 

 South of Long Island, U. S. B. F. Station 2234 

 Ofl Marthas Vineyard, U-S-B-F- Station 2222.. 

 Off Marthas Vineyard, U. S. B. F. Station 2094. . . 

 Off Marthas Vineyard, U- S. B. F. Station 2216. . . 

 Off Marthas Vineyard, U. S. B. F. Station 2093. . . 

 Off Marthas Vineyard, U. S. B. F. Station 207/. . . 



Off Nantucket, U. S. B . F. Station 2217 



Off Nantucket, U. S. B. F. Station 2195 



Off Nantucket, U. S. B. F. Station 2052 



Off Nantucket, U. S. B. F. Station 2051 



Off Nantucket, U. S. B. F. Station, 2050 



Oft- Nantucket, IT. S. B. F. Station 2193 



Off Nantucket, U. S. B. F. Station 2220 



OfF Nantucket U. S. B. F. Station 2192 



S of Block' llnd, U. S. B. F. Station 2209 . 

 South of Block Island, U. S. B. F. Station 2748. . 

 South of Block Island, U. S. B. F. Station 2210. . 



Block Island, U. S. B. F. Station 2205 



Block Island, U. S. B. F. Station 2207 



Block Island U. S. B. F. Station 2203 



Of! Delaware Bay, U. S. B. F. Station 2732 



Off Delaware Bay, U. S. B. F. Station 2733 



1 Off Delaware Bay, U. S. B. F. Station 2734 



' Off Delaware Bay, U. S. B. F. Station 2735 



6fl Ddaware Bay U. S. B. F. Station 2230 



Off Delaware Bay, U. S. B. F. Station 2103 



, Off Delaware Bay, U. S. B. F. Station 2102 



I ol Delaware Bay U. S-B.F. Station 2104 . - 



Off Chesapeake Bay, U S. B. F. Station 272,.. . 

 i Off Chesapeake Bay, U. S. B. F. Station 2728.. - 



Ofi Chesapeake Bay, U S. B. F. Station 2/31.. . 



Off Chesapeake Bay, U. S-B.F Station 2729- . 

 j Off Cape Hatteras, U. S. B. F. Station 2116 



Off Cape Hatteras, U. S. B. F. Station 2111 



852 fms., 38.4°, gy. m. 



l,255fms., 39°, bw. m. 



959 fms., 40°, gy. m. 



906fms., bw.m. 



1,290 fms., 40°, bw. m. s. 



1,813 fms.. 37°, glob. oz. 



810 fms., 39°, gn. m. • 



1,537 fms., 36.9°, gy. oz. 



1,022 fms., 38.5°, form. s. m. 



963 fms., 39.5°, gn. m. 



1,000 fms., 39°, form. s.m. 



1,255 fms., 39°, bw.m. 



924 fms., 38.1°, gn. m. 



1,0.58 fms., 38.4°, gn. m. 



1,098 fms., 45°, glob. oz. 



1 106 fms., 39°, bw. m. glob. oz. 



1^050 fms., 49°, glob. oz. 



1 122 fms., 38.4°, gn. m. 



1,054 fms., 38.3°, gy. m. 



1.060 fms., 38°, gy. oz. 

 1,080 fms., 39.5°, gn. m. s. 

 1,163 fms., 37.8°, gn. m. form. 

 991 fms., 38.1% glob. oz. 

 l,073,fms.,38.1°, gy.oz. 



1.061 fms., 38.6°, gn. m. 

 705 fms., 38.9°, gn. m. s. 

 1,152 fms., 38°, dk. gn. m. 

 944 fms., 38°, gn. m. 



841 fms., 38°, sft. gn. m. 

 811 fms., 38°, sft. gn. m. 

 1,168 fms., 36.8°, gy. oz. 

 1,091 fms., 39°, glob. oz. 

 1,209 sms., 39°, glob. oz. 

 991 fms., 41.5°, bw. m. 

 1,239 fms., 37°, gy. oz. 

 859 fms., 38°, gy.oz. 

 781 fms., 38°, gy. oz. 

 679 fms., 38°, dk. gn. m. 

 888 fms., 39°, bw. m. fne. s. 

 938 fms., gn. m. 



