Prcside7ifs Address. 55 



belong to this family witli Cypricardia. It is an oblong, 

 very inequilateral genus, with large hinge teeth, an external 

 cartilage, and is posteriorly radiated on the exterior. One 

 species, the Cypricardia ? tricostata (Portlock),* has been 

 described.-f- 



Although no true Solen is known from Scotch Carboni- 

 ferous rocks, the family is represented by a single small 

 genus called Solenopsis by M'Coy. Detailed investigation 

 will probably increase the number of these small solenoid 

 shells, as I have reason to believe one or two occur in 

 marine bands in tlie Calciferous Sandstone Series of the 

 east of Scotland. 



The last family of Carboniferous Bivalve shells which calls 

 for any notice is the most numerous in genera — the AnatinidcC, 

 containing the important genera Cardiomorplia (De Koninck), 

 Edmondia (De Koninck), Zeptodo?nus (M'Coy), Allorisma 

 (King), and Sanguinolites (M'Coy). 



The first of these comprises /socartZm-shaped shells with 

 an edentulous hinge, which did not survive the Carboniferous 

 period. Professor M'Coy instituted a genus in 1844 without 

 description, which he called Isocidia. This is believed by Dr 

 Stoliczka to be identical with Cardiomorpha. It will in no- 

 way affect the stability of De Koninck's genus. It is pro- 

 bably one of the best defined of the whole group, for other- 

 wise much confusion exists in the limitation of these genera. 

 We cannot hope for a more satisfactory solution of this 

 group, one of the most important of Carboniferous Bivalves, 

 until the whole of the species shall have been examined 

 collectively, and relegated to their proper genera. 



The genus Leptodomus was published by Professor M'Coy 

 in 1844,1 and comprised a group of shells totally differing 

 from that to which the name was applied in the second or 

 third fasciculus of his later work, " The British Pali?eozoic Fos- 

 sils." § Kepresentatives of both these occur in the Carboni- 

 ferous rocks of Scotland — the first by Leptodomus fragilis, is 

 considered to be probably identical with De Koninck's Cardio- 



* Geol. Report, Loiidondeny, 1843, p. 441. 



t King, Perm. Foss., p. 164, Note 3. 



% Synop. Garb. Lime. Fuss., Iielaml, p. 66. § Pp. 227 aud 568. 



