CLASS GASTROPODA 
41 
columella thin, arched; aperture rounded, sharp in front. (Conchologia 
I conic a.) 
Type in British Museum. Type locality, Sitka, Alaska. 
Range. Southern part of Bering Sea to Oregon. 
Trichotropis insignis Middendorff, 1849 
See Part II, Plate 31, figs. 9, 9 a 
Beitrage zu einer Malacologia Rossica, 107; PI. 10, figs. 7-9. 
Testa ovato-turrita, albescente; anfractibus confertim et grosse cari- 
nato-striatis, striis duabus prominentioribtis, sub-bicarinatis, angulatis; 
apertura ampla, ad carinas angulata. 
In der Gestalt stimmt diess Art mit der vorhergehenden, in der Skulp- 
tur aber nahe mit der folgenden uberuin. 
Long., 17; lat., 16; alt. anfr. ult., 13; lat. apertur, 9; colum. ext. long., 
8 mm. (Middendorff.) 
Shell thick, rather globose, covered with a pale brown epidermis, en¬ 
circled with undulating crenulated ribs; aperture rather square, with crenu- 
lated margin; umbilicus small. (Conchologia Iconica .) 
Type is in Academy, St. Petersburg. Type locality, Bering Strait. 
Range. Bering Strait, Aleutian Islands, and Cooks Inlet, Alaska. Also 
Japan. 
Subgenus Ipiiinoe H. and A. Adams, 1854 
Trichotropis coronata Gould, 1860 
See Part II, Plate 31, fig. 7 
Proceedings of the Boston Society of Natural History , 7:324. Tryon, Manual of Con- 
chology , 9: PI. 7, figs. 53, 54. 
T. ovato-rhomboidea, turrita, tenui, cinerea, epidermide fibroso ad 
carinam in fimbriam cirrosam producto induta; umbilico lato, profundo, 
acute marginato; anfr. 6 cito crescentibus, postice tabulatis ad angulum 
carinatis: apertura ovato-triangularis, labro simplici; columella recta, antice 
vix reflexa, acuta, subcanaliculata; operculum ovatum, corneum, apice 
terminali. Long., 25; lat., 15 mm. (Gould.) 
Umbilicus rather wide and deep, acutely margined; whorls about six, 
tabulate and carinate at the angle; epidermis ash-colored, fibrously pro¬ 
duced at the angle. (Tryon.) 
Type in United States National Museum. Type locality, Straits of 
Semiavine, Arctic Ocean, in 20 fathoms. 
Range. Arctic Ocean and Bering Sea. 
[643 ] 
