35.0 Description of some nondescript and rare 



Our figures exhibit the animal of its natural size; and 

 were taken from specimens found, between tide-marks, in 

 Berwick Bay. Like the land slug, it progresses by obscure 

 undulatory motions of the foot ; but it justly claims the " bad 

 preeminence " of being superior in sluggishness and tardiness. 



The specific name of Blainville is unjustifiable ; and no 

 authority can warrant our adoption of it. Montagu (the 

 discoverer of the species) called it Bulla plumula * ; and, 

 although the generic name must be altered to suit the progress 

 of science, his specific name is sacred, and is beyond the 

 changeful caprice of any systematise Blainville has done 

 some further wrong to Montagu, in ascribing even the dis- 

 covery of the mollusc to Donovan ; whose name, I may 

 observe, is often substituted for that of the former naturalist 

 by foreign authors, and by some careless translators in our 

 own country. BermcJc upon Tweedy Jan, 3. 1834^. 



Art. VIII. Description of some nondescript and rare British Species 

 of Shells, By William Turton, Esq. M.D. &c. 



Crena'tula Travi's// [Turton]. (Jig, 47.) 



Testa rhombea, inferne rotundata, pellucida, albida vittis 

 longitudinalibus interruptis pallide violaceis ,• margine antico 

 incurvato. 



Shell rhombic, rounded below, transparent, whitish, with 

 pale, violet, longitudinal, interrupted stripes; the anterior 

 margin incurved. Nearly an inch long, and full half an inch 

 broad ; extremely thin and brittle ; obliquely truncate at the 

 top, with a few pale violet spots below ; hollowed out at the 

 front margin in a slight crescent-shaped form. 



This most interesting addition to our native stock was 

 taken alive at Scarborough; and is in the cabinet of Mr. 

 Bean, who obligingly sent the accurate drawing from which 

 the figure was taken. He has given it the specific name of 

 TraviszV, after Mr. Travis, well known for his valuable com- 

 munications to Pennant. In its outline, it differs from any 

 of those figured by Sowerby, or described by Lamarck. 



My'tilus stria'tulus Linn, Mant, p. 548., Schrcet, Einl, iii. 

 p. 449. t. 9. fig. 16., Gmel p. 3358. 



Testa subtrigona, striis longitudinalibus elevatis crenulatis. 



Shell somewhat triangular, with raised, longitudinal, slightly crenate 

 striae. 



Length three quarters of an inch, and hardly as much in breadth ; semi- 

 transparent, dark horn-colour, with a few paler zones ; marked with nume- 



■* He subsequently constituted with it a new genus, which he called 

 Lamellaria, a name preoccupied in botany. 



