486 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 45. 



From D. tuherculata, adolpJii is sharply distinguished in external 

 features first of all by the distinct, though short wart-like siphons of 

 the latter species. Furthermore, the body of adolpTii is more nearly 

 spherical, more regular, the test is more delicate, and the color is 

 Tighter. Internally the small number of gonad branches in adolpTii 

 sharply distinguishes the species from tuherculata. 



D. adolphi was originally described from Shannon Island, near the 

 coast of Greenland, and has not been reported from any other locality 

 until now. There are about 150- specimens, large and small, in the 

 one lot,taken at Cape Etolin, Nunivak, Alaska, by Dr. W. H. Dall in 

 8 fathoms. 



PELONAIA CORRUGATA Goodsir and Forbes. 



Pelonaia corrugata Goodsir and Forbes, 1841, p. 30, pi. 1, fig. 1. — Alder and 

 Hancock, 1907, vol. 2, p. 145, pi. 46, figs. 15, 16; pi. 47; pi. 48, fig. 18; text 

 figs. 81 and 82.— Hartmeyer, 1903, p. 203, pi. 5, fig. 14.— Huntsman, 1911, 

 p. 132.— Van Name, 1912, p. 545, text fig. 29; pi. 58, figs. 84, 85. 



The early synonymy of this species is given in detail by Alder and 

 Hancock, by Hartmeyer, and by Van Name. 



After working with specimens so equivocal in their characters as 

 compared with their kindred as to drive one ahnost to madness to 

 know what disposition to make of them, it is a great pleasure to come 

 upon a lot of individuals like those now in hand, that are no more 

 dubious as to their place in the scheme of classification than are 

 recently minted pieces of money. 



It is certainly worthy of note that in spite of the wide distribution 

 of Pelonaia corrugata, it being circumpolar in the Arctic Ocean, and 

 extendmg as far south in the Atlantic as the British Islands m Europe, 

 and the New England coast in North America; and in spite of its 

 having been so long known and collected and studied by so many 

 zoologists, it has never seemingly been assigned to any other genus. 



Albatross 3253, 36 fathoms, mud and sand bottom, lat. 57° 05' 50'' 

 N.; long. 164° 27' 15" W. (southeastern Bering Sea); June 14, 1890. 

 A single specimen. 



U. S. R. S. Corwin 1880, 2 specimens (no further data). 



CHELYOSOMA COLUMBIANUM Huntsman. 



Chelyosoma columbianum Huntsman, 1911, p. 124. 



The character upon which Huntsman has chiefly reUed to distin- 

 guish this species from C. productum is the presence of short stout 

 muscle fibers comiecting the central plates. Such fibers are present 

 in the specimens now under examination; and since they seem, from 

 the extensive study of the musculature by Bancroft, 1898, to be 

 whoUy wanting in the typical Chelyosomas of Puget Sound and the 

 regions southward, columbianum stands by this character alone as a 

 well-marked species. But the specimens at hand bear out Huntsman's 



