OF CONCHOLOGT. 145 



I hardly know with what species to compare this very distinct 

 form. It is perhaps nearest to S. flavicans, Gld., from Panama, 

 which wants the red lines, is more rounded and higher, with a 

 shorter lunule, and much narrower and smaller pallial sinus, 

 besides many other differences. 



It has not the peculiar spongy surface of decisa, which is a very 

 high round shell, with the interior strongly punctate and valves 

 nearly equilateral. It wants the curious sculpture, color, and 

 form of S. rupium, which has also a rounder shell and smaller 

 mantle bend. It bears no resemblance to S. incongrua, Cpr., 

 and has not the sculpture or painting of S. pulehra. 



VENERIDiE. 



LIOCYMA, Dall. 



Liocyma, Dall, Proc. Bost. Soc. Nat. Hist., xiii, p. 256, 

 April, 1870. 



1. Type Liocyma fluctuosa, Gld. 



Habitat. Ochotsk Sea ; Grand Banks, Newfoundland, Nova 

 Scotia ; Mass. Bay. 



Characters compressed, regularly waved, with faint radiating 

 striae ; subovate waxen yellow. Animal pale yellowish white. 



2. Liocyma Beckii, Dall. 



Liocyma Beckii, Dall, Proc. Soc. Bost. Soc. Nat. Hist., xiii, 

 p. 257, 1870. 



Habitat. Plover Bay, E. Siberia ; Kadiak ; Unga Island, 

 N. Pacific. 



Characters. Inflated, subtrigonal, waves somewhat irregular, 

 without striae, straw yellow. Animal white with pink siphons. 



3. Liocyma ? arctica, Rve. 



Tapes arctica, Rve., Conch. Icon., x. sp. 52, 1865. 



Habitat. Arctic Seas. (Ubi.) 



Characters. Compressed, cuneiform ; slightly irregularly 

 waved ; ashy green ; with radiating darker lines of color ; with- 

 out striae. Animal ? 



This species probably belongs to this genus, but differs in 

 shape and sculpture from the others. 



4. Liocyma Scammoni, n. s. 



Anaitis ? Scammoni, Dall, MSS., 1868. 



Shell most resembling L. fluctuosa, but less compressed, much 



