Mollusks. 



5381 



Modiola phaseolina. Larnlash, Landshorough. 



Crenella discors [Modiola discrepans). The young very abundant 

 among Corallina in rock-pools ; large specimens, however, rare. A 

 small stunted form is found at the outer Allans, Cumbrae. 



* „ marmorata (Modiola discors). Ayr, Smith. Not rare 

 within the tunic of Ascidia mentula. From a single specimen of this 

 Ascidia, dredged at Cumbrae, I extracted no less than eleven Cre- 

 nellae, some of them very large, such as I have never seen except 

 from the West of Scotland. Dr. Landshorough mentions that Major 

 Martin has dredged this species near the Corriegills, buried in the 

 coriaceous coat of Ascidia rustica " (Lands. Excurs, p. 49). 



decussata. Larnlash, Landshorough, 



Fam. XVIII. Arcada. 



*Nucula Nucleus [Nucula margaritacea). Common throughout 

 the district in suitable localities : Largs, Fairleigh, Cumbrae, Rothe- 

 say, Lam lash, Ayr. 



„ nitida. t have taken one or two specimens at Cumbrae, 

 but it appears to be very rare. Bute, Smith; Larnlash, Lafidsborough. 



„ radiata. "Lamlash, Arran (Alder)," F. 8$ H. 



* „ tenuis. Forbes and Hanley inform us that " this essen- 

 tially northern species" occurs in the Clyde district. Mr. Smith 

 records it from Bute, and Dr. Landshorough from Lamlash. It must, 

 however, certainly be very rare, as it has never fallen to my lot to 

 meet with it. 



*Leda caudata {Nucula minuta, Nucula rostrata). Very rare. 

 Clyde, Bute, Smith ; Lamlash, Landshorough) . A single living spe- 

 cimen is now in my cabinet, which was dredged by Mr. W. Templer 

 at Largs, and given me by Dr. Lowe. 



* „ oblonga {Nucula ohlonga). Ayr, Smith. 



„ truncata {Nucula truncata). Ayr, Smith. On this and 

 the last-mentioned species, admitted by Mr. Smith, of Jordan Hill, 

 into his catalogue of the recent shells of the Clyde, Forbes and Han- 

 ley thus write ; — " In consequence of the pleistocene tertiary beds of 

 clay on the west coast of Scotland being often laid bare below low- 

 water mark, fossil shells are frequently brought up in the dredge along 

 with recent ones, and as often cast on the shore. Owing to their ex- 

 tremely fresh appearance, even the epidermis in many instances being 

 preserved with its pristine colours and lustre, it is very difficult to say 

 at a glance whether such specimens be not the exuvia; of animals yet 

 living in the neighbourhood. This difficulty is yet further increased 

 XVI. E 



