302 MOLLUSKS OF BERING SEA. 



ish. Greatest length of shell 13.0, of aperture 8.0 ; greatest breadth of 

 shell T.O'"™. 



This very characteristic species seems to have no analogue in Euro- 

 pean seas. It is found abundantly in the western Aleutians, generally 

 in about ten fathoms, and especially on a sandy bottom. It does not go 

 into truly arctic waters and varies less than most of the genus. The 

 type figured came from the harbor of Kyska. 



Tliere are a large number of undetermined species of Bela from Ber- 

 ing Sea in the collection, sotne of which will probably prove new, but 

 I have thought best to refer only to those ^bout whose novelty there 

 seemed to be no question. The group is one of the most difiBcult to 

 determine on account of the variability of some of the species, many of 

 which have also well-defined large and small races, otherwise similar 

 in all respects. 



Sipho martensi Krause. 



S. martensi Ki-ause, 1. c, p. 287, pi. xviii, fig. 18, 1885. Dall, 1. c. , p. 525, 1884, 

 Fusus {Eiilhria) comdug Aurivillius, Vega Exp. vet. arb., iv, p. 354, pi. 13, fig. 6^ 



1885. 



This fine species has received two names, almost simnltaneonsly. I 

 am not aware which has precedence, but the species was referred to^ 

 under the name of martensi^ by me before either description was pub- 

 lished, as above mentioned. It seems to be a strictly Arctic species, 

 and was obtained by the Vega off' Cape Shelagskoi in twelve fathoms^ 

 and southwest of St. Lawrence Island, in Bering Sea, in fifty-five fath- 

 oms. I obtained it in the Arctic Ocean, north of Bering Strait, in 

 twenty fathoms, mud, in 1880. Notwithstanding the shape of tlie shell 

 I doubt its being a typical Uuthria, none of which are known from 

 northern seas. 



Trophon muriciformis Dall. (PI. IV, fig. 6.) 



Trophon DalH Kobelt, Mou. Trophon, Mart. & Chemn. Neueste ausg., q. v. 



This fine shell has been renamed by my friend Dr. Kobelt on account 

 of the existence of a shell, which he refers to Trophon, but which Amer- 

 ican conchologists refer to Stimpson's genus Eiipleura, namely, the Bug- 

 cinum muriciforme of King and Broderip (Zool. Journ., v, p. 348). The 

 T. muriciformis has not been well figured, tbe only specimen I had to 

 spare Dr. Kobelt being worn and discolored by a growth of HaUsarca^ 

 while that figured by Aurivillius is evidentlj^ somewhat worn. 



In the colored copies of Tryou's Mauual I find it figured of a dull 

 green, perhaps copied from Kobelt's figure, but when in good condition 

 the shell itself is of a creamy translucent white, with a chalky suj)er- 

 ficial stratum. In some specimens the triangular spines are continuous, 

 with hardly raised lamellse; but in the original type the lamellai are 

 hardly visible, and the spines, showing somewhat tianslu«'ent, project 

 from the opaque white surface as if they had been stuck on artificially. 

 It is a native of the Arctic coast of Alaska, and very rare. The Vega 



