T R I C II T R P I S. 



Genus TRICIIOTROPIS, Drodcrip and Sowcrhj. 



2'esta spiralis, carinata, umbilicata, cpidermide corneo 

 induta ; spirm anfractibus scalatis ; aperhird niagnd, 

 antice acuminatd canaliferd. Operculum corneum, 

 nonspirali, micleo tcrminali. 



Shell spiral, keeled, umbilicatcd, covered with a horny 

 epidermis ; whorls of the spire in steps ; aperture 

 large, acuminated anteriorly, with a canal. Oper- 

 culum horny, not spiral, with terminal nucleus. 



Three or four species out of the thirteen are from 

 Japan, &c., the others are from the northern latitudes 

 of Em-ope and America. The species of Admete are 

 distinguislied from those of Trichotropis, not only by 

 the lighter texture, and usually more ovate form of the 

 shell, but by the absence of an umbilicus. 



•Species 1. (Fig. «, h, c, Brit. Mus.) 



Trichotropis Borealis. Tri. testd siibj'usijbrmi, laid 

 umbilicafd, quinquc-carinatd, epidermide crasso, 

 flamidi fusco, ad carinas hirsuto indutd, infiis 

 rofed ; spiird elevatd ; anfractibus paucis, angulatis ; 

 aperturd lata, columella obliqud, labio externa tenui, 

 angulato. 



The Boreal Trichotropis. Shell subfu.siform, broadly 

 umbilicated, five-keeled, covered with a thick 

 yeUow-brown epidermis, with hair at the keels, 

 pink within ; spire elevated ; whorls few, angular ; 

 aperture broad, columella olilique, outer lip tliin, 

 angukir. 



Broiieijip and Sowerey. Zool. Journ. iv. p. 37.5. 



Trichotropis Atlantica. Beck. 



Trichotropis umbilicata. Macgillivray. 



Trichotropis acuminata. Jeffreys. (Fig. 1, a.) 



Eab. Behring Straits, Greenland, North Britain. 



The synonyms above quoted appear to be only 

 conditions and states of the same species. The 

 second is represented by our figure 1 a. The third is 

 figured in Thorpe's British Marine Gonchology as 

 having all the appearance of an unformed shell. 



Species 2. (Mus. Sowerby.) 



Trichotropis bicarinata. Tri. testd angulato-suhglo- 

 bosd ; anfractibus angulatis, pauci.% ultimo maximo, 

 medio carinis diuthas cilialis, distaiUibus cinctis ; 

 umbilico lata, inai ijini' filiiiln ; apcrtiin'i rnaxlmd, 

 subquadrati'i, coliiiinlht latd, iiifhi plamitd, expansd. 

 Epidermide flavide fused. 



The two-keeled Trichotropis. Shell angular-subglo- 

 bose ; whorls angular, few ; last very large, en- 

 circled with two ciliated, distant keels ; um- 

 bilicus broad, with ciliated margin ; aperture very 

 large, rather square. Epidermis yellowish-brown. 



Broderip and Sowerby. Zool. Journ., iv. 



Hnb. Japan. 



Specie 



(M. 



5rit.) 



Trichotropis cancellata. Tri. testd pyramidatd ; 

 spird elevatd ; anfractibus sitbrotundis, ultimo ven- 

 tricoso, costellis seto crenulatis, ciliatis cincto ; um- 

 bilico parvo ; columella tenui, arcuatd ; aperturd 

 rotunda, antice acutd. 



The cancellated Trichotropis. Shell pyramidal; 

 spire elevated ; whorls rather rounded, last whorl 

 ventricose, encircled with eight crenulated, 

 ciliated ribs; umbilicus small ; columella thin, 

 arched ; aperture rounded, sharp in I'ront. 



Hinds. Proc. Zool. Soc, 1843. 



Hab. Sitka, North America. 



August, 1S74. 



