5886 



Mollusks. 



The variety parasitica occurs at Lamlash, and may be procured also 

 from the rocks, at low-water mark, in Balloch Bay, Cumbrae. 



*Anomia ephippium [Anoniia squamiila and cylindrica). Never 

 occurs of large size, the variety squamula being the most common 

 form. 



* 5, aculeata. Rare. Bute, Smith ; Cumbrae, Lamlash. 



* „ patelliformis [Anomia undulata). Very rare. I have 

 only procured two or three specimens. 



„ striata. 1 have formerly sent this shell to many of my 

 correspondents under the name of " patelliformis." My attention was 

 kindly called to its being the true striata by my friend Mr. Webster. 

 I have little doubt in my own mind as to the specific identity of these 

 two shells, believing that the modifications which their form assumes 

 are merely due to local causes of food and habitat. I am far, however, 

 from prepared to go the length of Mr. Clark, who, taking up his posi- 

 tion solely on malachological grounds, would unite all the British 

 Anomiae under one species ; indeed, in order to reconcile the mala- 

 chological differences which exist between the species, Mr. Clark is 

 driven to compare a few isolated specimens of the young of patelli- 

 formis with fiill-grown ephippium. Anomia striata is abundant in the 

 Clyde, and is found for the most part attached to the interiors of Pec- 

 ten shells, though now and then living on the exterior ; and in some 

 localities (as outside the Bay of Lamlash) it lives upon stones. Ex- 

 amples from these last situations are not developed so evenly in all 

 their parts as those found in the interior of bivalves, and present a 

 rougher and coarser aspect; some now and then living on the edges 

 of stones, and not having room to develope themselves, assume a 

 tubular saddle-shaped form. 



Div. IIL Palliobranchiata. 

 Fam. 1. Terehratulido}. 



Terebratula caputserpentis (Terehratula auriia). The only loca- 

 lity which has at present yielded this species in the Clyde is around 

 Holy Island, more especially to the north-east, and between that and 

 Hamilton's Rock. Clyde specimens are smaller, more ventricose, 

 and have the costellse larger and fewer in number than is usual in 

 those taken among the Hebrides. 



Fam. II. Craniadce. 



Crania anomala {Orhicula normgica^ Crania norvegica and perso- 

 nata). This remarkable bivalve (which it is impossible to make a 



