494 Mr. G. B. Sowerby on two new species ofCt/prcea, 



The specimen from which our representation is taken was 

 obligingly communicated by H. T. De la Beche, Esq., it is from 

 the indurated nodules (called in the country " Cowstones") con- 

 tained in the lowest green sand of Lyme Regis; it is in Miss E. 

 Phillpot's collection. 



The genus Astacus being divided, according to Desmarest, into 

 two sections, the species of which are respectively inhabitants of 

 the sea, (Lobsters) and rivers (Crayfish) the present species may 

 be considered as belonging to the marine section. 



Both the claws are rather rough : the superior external edge of 

 the left hand has a longitudinal groove and the inner edge a few 

 tubercular spines : the finger as well as that part of the thumb of the 

 left hand opposite to it are armed with small, regular teeth on the 

 inner edge ; both are much attenuated and elongated. The right 

 claw is more robust than the left : the outer edge of the thumb 

 has a longitudinal groove, both above and below, and the inner 

 edges of the finger as well as of its thumb are armed with a few 

 large tubercles. The outer edges of the central segment of the 

 terminal flap of the tail are serrated with a few small sharp teeth. 

 Thorax with a few small pointed spines and a deep lunulate groove 

 on each side in front ; smooth and finely granulated behind. 

 Abdomen smooth, with minute distant punctulations on the upper 

 part. Terminal flap of the tail or abdomen rather rugose. 



Art. LVL Descriptions of two new Species of Ci/prasay 

 principalli/ extracted from " A Catalogue of the Shells 

 in the Collection of the late Earl of Tanfcerville.^* Bt/ 

 G. B. Sowerby, F.L.S., S^c. 



Cypr^a umbilicata, 

 C. testa oblongo-ovata, basi acuminati, superne subrostrata, 

 umbilicat^ ; dorso ventricoso, pallido, fusco-maculato ; ventre 

 subrotundato, albido ; marginibus rotuhdatis, albidis, fusco-macu- 

 latis; apertur^, dentibusque subdistantibus, pallidissime sub- 

 fuscis : long. 3 ^ poll. lat. 2 ^ poll. 



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