Mollusks 21 A 



and Apiexa hypnorum, abound to the very verge of .the Polar sea, it seems 

 difficult to account for the absence of Physa, elsewhere associated with them. 



Genus Lora Gistel. 

 Lora trevelliana Turton. 



Pleurotoma treveilianum Turton, Mag. Nat. Hist., VII, p. 351, 1841. 



Mangelia treveLtiana Forbes & Hanley, III, p. 452, pi. 112, f. 12, 1853. 



Pleurotoma reticulata Brown, 1827, not of Renieri, 1804. 



Station 27s. Off Collinson point, Alaskan Arctic coast, in three fathoms. 



Also on the Murman and North Atlantic coast. 



Several specimens apparently not quite full grown were obtained. They 

 agree with British specimens except that the sculpture is more feeble than in the 

 completely adult individuals. Jeffreys notes that American specimens are 

 smaller than those from Britain, as is also the case with some other mollusks. 



Genus Admete Kroyer. 

 Admete elongata Leche. 



Admete viridula Fabr. var. elongata Leche, K. Svenska Vet. Ak. Handl. Bd. 

 16, No. 2, p. 48, pi. 1, fig. 13, 1878. 



A badly eroded specimen was obtained at station 23, off the Sea Horse 

 islands, Alaska, N. Latitude 70 24', in 9-10 fathoms, sandy bottom. This 

 appears to be the shell described in the report of the Swedish expedition to Novaia 

 Zemlia and the Yenisei in 1875 and 1876 under the name above cited. If it is 

 really an Admete the plaits on the pillar are obsolete, but the specimen is too 

 imperfect to base a dogmatic opinion upon. Long since it was pointed out that 

 the type specimen of Fabricius' shell is a Beta, a fact which I have verified by 

 personal inspection. Also that the Admete was first named costellifera by 

 J. Sowerby in 1818 from a Crag fossil. The present shell has much the aspect 

 of a Trichotropis, and certainly has not the least connection with Admete 

 costettifera, or Admete viridula auct. non Fabricius. 



Genus Plicifusus Dall. 

 Plicifusus johanseni, n. sp. (PL III.) 



Shell fusiform, whitish, with six or more slightly rounded whorls exclusive 

 of the (lost) nucleus; suture distinct, not appressed or channelled; but rather 

 deep; the first three or four whorls are feebly axially plicate, the obscure riblets 

 anteriorly protractive and varying in number up to ten; very faint irregular 

 traces of them, or some of them, may appear on the last whorl; spiral sculpture 

 of numerous straplike flat spirals made duplex by a medial groove and separated 

 by a much narrower interspace crossed by fine incremental lines; canal short, 

 slightly recurved; outer lip arcuate, somewhat produced below the periphery; 

 body and pillar with a coating of enamel; pillar attenuated in front, nearly 

 straight. Length of (decollate) specimen 52; of last whorl 39; of aperture 26; 

 max. diameter 22 mm. 



Station 24. Point Barrow sandspit, Alaska. Also collected at Icy Cape, 

 Alaska, by Capt. Everett Smith, in 1874, who presented a specimen to the U. S. 

 National Museum. 



The expedition collected a dilapidated specimen at Point Barrow, but I 

 have drawn up the' description from the better preserved individual in the 

 collection of the U. S. National Museum. Catalogue No. 4117 (Ottawa). 



