LAND AND FRESH- WATER MOLLUSCA OF GREENOCK. 283 



observed in truly decollated shells, such as Bulhnus 

 decollatus. Possibly, however, we may have come 

 on them too soon for that to have taken place ; or 

 perhaps the closing up of the broken end would be 

 an after consideration, especially if it were found 

 that there was some danger of an attack being made 

 on the animal from behind; or perhaps it was a 

 ^' new departure " — an experiment as to the econo- 

 mising of space in order to lighten as much as 

 possible the burden that had to be carried, so that 

 the " struggle for existence " might be engaged in 

 with a greater likelihood of success ; — but the work- 

 ing out of these abstruse questions I leave to those 

 with more subtile intellects. 



Among the rarer species, for which new stations 

 are recorded, is Acme lineata, which my son found 

 near the Cloch in 1881. In the following year he 

 found another specimen about the same j)lace, but 

 it was partially crushed. Of the species and varieties 

 mentioned in the annexed List, the only form which 

 I do not possess or have not seen is Zonites pulsus 

 var. Tnargaritaceaj for which, in the 1876 list, the 

 «Cloch is given as a habitat. 



I have to acknowledge my obligation to the late 

 Dr. Gwyn Jeffreys for his kindness in identifying 

 a few of the rarer and more critical species men- 

 tioned in this List. 



The arrangement of the Conchological Society s 

 List of British Land and Fresh-water Mollusca (1883) 

 has been generally followed. 



List of Laiid and Fresli-ioater Mollusca of Greenock and 

 surrounding District. 



CONCHIFERA. 

 SPHJERIID^. 



PiSlDiUM FONTINALE (Drap.), var. PULCHELLA, Jenyns. — Moss- 

 clave pond, near Greenock. 

 PUSILLUM (Gmel.). — Mossclave pond, and other places. 

 NITIDUM, Jenyns. — Pools, side of Kilmalcolm road, near 

 Port-Glasgow. 



