98 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 109 



that these shells are identical with what they call B. clathratus and 

 that the smaller specimens sent him are B. clathratus var. gunneri. 

 The latter are angiilated and are undoubtedly the forms that Gould 

 described as having varices more elevated at the posterior part of the 

 whorls. 



The number of varices is a highly variable character in the northern 

 species of Boreotrophon. Some varices may be three times as far 

 apart as others on the same whorl and still others may be so close 

 together that they give the appearance of a double varix. 



At Point Barrow 2 capsules, each containing 2 embryos, of a species 

 of Boreotrophon were dredged at Eluitkak Pass on Aug. 30, 1948. 



Boreotrophon cUithratus (Linnaeus, 1767) 

 And vara, gunneri Lov6n and scalariformis Gould 



Plate 7, figures 1-7 



Murex clathratus Linnaeus, 1767, ed. 12, p. 1223. 



Murex rrndticostatus Eschscholtz, 1829, pt. 2, p. 11, pi. 9, fig. 4. 



Fusus lamellosus Gray, 1839, p. 117, pi. 36, fig. 13. 



Tritonium gunneri Lov6n, 1846, p. 144. 



Fusus scalariformis Gould, 1840, p. 197; 1841, p. 288, fig. 203. 



Trophon clathratus G. Sars, 1878, p. 247, pi. 15, fig. 10 (■= type).— Morris, 1947, 



p. 144, pi. 39, fig. 15; 1951, p. 184, pi. 39, fig. 15 (■= var. gunneri). 

 Trophon clathratus var. gunneri G. Sars, 1878, p. 247, pi. 15, figs. 11, 11a. 

 Trophon scalariformis Bartsch, 1921, p. 87. — Morris, 1947, p. 144, pi. 39, fig. 11; 



1951, p. 185, pi. 39, fig. 11. 

 Boreotrophon multicostatus Abbott, 1954, p. 207, fig. 46c ("= var. gunneri Lov6n). 



Eighteen living and 3 dead specimens were dredged at depths of 

 110 to 741 feet. The depths of 125, 184, and 295 feet yielded 3 

 specimens each, and those of 110 (Sept. 15, 1948), 420, and 741 feet 

 yielded two each. The 2 largest specimens are 39.5 mm. long; the 

 smallest, 28 mm. Foraminifers and hydroids are common on these 

 shells. 



The var. gunneri Loven is represented by 8 living and 5 dead speci- 

 mens from depths of 80 to 741 feet, 4 of the living specimens coming 

 from depths of 438 to 741 feet. The largest living specimen is 28.5 

 mm. long; the smallest, 18.5 mm. Foraminifers and hydroids are 

 common on these shells also. 



Other material examined. — About 30 specimens of B. clathratus 

 from St. Peter's Bank, the Grand Banks, and Newfoundland; 1 from 

 Massachusetts Bay; about 15 from western Greenland; and 1 from 

 Spitzbergen. 



Discussion. — There are variations in the length and arcuateness of 

 the canal and in the degree to which it is reflected; there are from 15 to 

 19 varices in the Point Barrow specimens of B. clathratus. One speci- 



