552 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
shape. The testes are variable in size, number, and position. Some 
He close to the ovary, some at a distance from it. Sperm ducts may 
be traced leading from them to or toward the ovary, and probably 
unite to a common duct following that organ. A small papilla on the 
side of the ovary near the anterior end of the latter is noticeable in 
some cases and is probably, as in related species, the termination of 
the sperm duct. 
This is a widely distributed, species in the high latitudes (Redi- 
korzew, 1908b, p. 32) recorded it from the coast of Norway, Spitz- 
bergen, Barents Sea, Murman Coast, Nova Zembla, White Sea, 
Siberian Arctic Ocean, Baffin's Bay, Davis Strait, Greenland, Iceland, 
Faroe Islands, and the coast of Denmark and Germany. It inhabits 
bottoms of various characters in depths of from 2 to 432 meters. 
There are numerous specimens of this species in the collections from 
the Banks of Newfoundland and a few small ones from Murray Bay, 
Gulf of Saint Lawrence, and Labrador. It is abundant at Murray 
Bay according to Whiteaves (1901). There is also a small lot of 
specimens from the Gulf of Saint Lawrence between Pictou Island and 
Cape Bear, collected by Dr. Whiteaves, which are peculiar in their 
dorso-ventrally flattened form, small size, and finely wrinkled surface. 
They have the low conical shape (in two cases almost disk-like), com- 
mon in Tethyum coriaceum and Dendrodoa carnca described elsewhere 
in this article, yet the constant presence of the pointed processes of 
the test, and the close correspondence of their internal anatomy with 
that of the specimens from the Grand Banks appears sufficiently to 
prove their identity with this species. The largest of them measures 
about 22 mm. across the upper surface. On the New England coast 
the species has not been found. 
Tethyum atlanticum, sp. no v. 
PI. 59, figs. 92, 93; PL 60, fig. 96; PI. 68, fig. 135; text-fig. 31. 
1885. Cynthia partita ("apparently") Verrill, Rept. U. S. Comm. Fish and 
Fisheries for 1883, p. 529. 
In form, size, and character of the test often practicably indistin- 
guishable from T. rusticum except that the pointed process between 
the apertures which is frequently present in that species does not 
occur in this one. The lining of the test is whitish or bluish white in 
many specimens. 
