1881. J 'lightning* AND 'porcupine* EXPEDITIONS. 717 



Distribution. S. England, Bristol Channel, E.,W., andS. Ireland, 

 Atlantic coasts of France and Spain, Mogador, throughout the 

 Mediterranean, Black Sea, Adriatic, Madeira, Canaries ; 0-20 

 fms. 



Fossil. Miocene : Vienna Basin. Pliocene : Coralline and Red 

 Crag, S. France, Italy, Morea. Post-tertiary : Calabria, Rhodes. 



On consideration I must include this genus in the Fenus family, 

 although its position is not quite satisfactory. It is in some respects 

 allied to Tapes, and in others to Saxieava. 



\/ 1. Tapes virgineus, Linne. 



Venus vircjinea, L. S. N. p. 1136 (according to modern authors). 



Tapes virgineus, B. C. ii. p. 352, pi. vi. f . 5 ; v. p. 185, pi. xxxix- 

 f. 5. 



* Porcupine ' Exp. 1869 : St. Donegal B., Lough Swilly, L. Foyle. 

 Atl. Vigo B., C. Sagres, Tangier B. ; Med. Capo de Gata (var. sar- 

 niensis), 55, 58. 



Distribution. Finmark and Faroe Is. to E. Mediterranean and 

 Adriatic; 0-180 fms. 



Fossil. Miocene: Prussia, Vienna Basin, Transylvania, Switzer- 

 land, Turin, Calabria, Lisbon, Bordeaux Basin, Madeira (as T. hoer- 

 nesi) ? Upper Tertiaries and Post-tertiary : Scandinavia, British 

 Isles, Italy, Greece, Rhodes ; 0-50 ft. 



I have collated no less than twenty-two synonyms. The very 

 young are not unlike those of Venus chione. 



t^ 2. Tapes geographicus, Chemnitz. 



Venus geoc/raphictt, Chemn. Conch. Cab. vii. p. 45, t. 42. f. 440. 



Tapes pullastra, B. C. ii. p. 355; v. p. 185, pi. xxxix. f. 6. 



•Porcupine' Exp. 1869 : St. Donegal B. 1870 : Med. 50, 50 a. 



Distribution. Finmark to Alexandria, Adriatic, Mogador, Cape of 

 Good Hope, Japan ; 0-45 fms. 



Fossil. Upper Tertiaries and Post-tertiary : Scandinavia, British 

 Isles, Mewe near Konigsberg, Italy; 0-1360 ft. 



More than a dozen synonyms, including Venus pullastra of Mon- 

 tagu. Since the publication of my last volume of ' British Concho- 

 logy,' I have examined many hundred specimens of the southern 

 form, 2'. geographicus, from the Mediterranean and Adriatic ; and 

 my former opinion (vol. ii. p. 359) of its being the same species as 

 the northern form, T. pullastra, lias been most fully and satisfac- 

 torily confirmed. There is not the slightest difference, except in 

 size, between specimens from the north and south of Europe. But 

 inasmuch as Chemnitz's name geographicus is far older than that of 

 Montagu, I have wo alternative but to substitute the former name 

 for pullastra. It is possible that this species may be partly the 

 Venus literata of Linne, who gave Europe as well as India as the 

 habitat, and cited the 'Fauna Suecica' and Gualter's figure of T. 

 geographicus. 



