558 DR. GWYN JEFFREYS ON THE MOLLUSCA OF THE [Jlllie 17, 



Distribution. Loffoden I. to the Morea, Malta, and the Adriatic ; 

 20-470 fms. 



Fossil. Pliocene and Post-tertiary. Coralline Crag, Belgium, 

 Biot, Messina ; 0-30 ft. 



Ostrea arata of Gmelin and P. bruei of Payraudeau. When I 

 adopted Gmelin' s specific name, I overlooked the relative dates of 

 Midler's and Born's publications ; that of Miiller is anterior by two 

 years, viz. 1776, while Born's was 1778. Midler's description, 

 although short, is unmistakable. 



y 7. Pecten opercularis, Linne. 



Ostrea opercularis, L. S. N. p. 1147. 



P. opercularis, B. C. ii. p. 59, pi. ii. f. 1 ; v. p. 1GG, pi. xxii. 

 f. 3, 3a. 



'Lightning' Exp.: St. 4. 



' Porcupine' Exp. 18C9 : St. 2, 33, 35. 1870 : Atl. 1, 2,3, S, 9, 

 10, Setubal B., C. Sagres, 26, 3G, Tangier B. ; Med. 50, 55, G. Bona, 

 Benzert Road, Rasel Amoush, G. Tunis, Adventure Bank, off 

 Rinaldo's Chair. Specimens have a more or less strongly imbricated 

 sculpture. 



Distribution. Iceland to the Sea of Marmora, Adriatic, Madeira, 

 Canaries, and the Azores ; 5-205 fms. The depth recorded for the 

 variety audouinii from the Mediterranean cable is questionable. 



Fossil. Pliocene and Post-tertiary. Scandinavia, Great Britain 

 and Ireland, Belgium, N. Germany, S. France, Italy, Algeria, 

 Morea, Rhodes, Madeira ; 0-600 ft. 



8. Pecten philippii, Recluz. 



P. philippii, Reel. Journ. de Conch, iv. p. 52, t. ii. f. 15, 16 



(1853). 



'Porcupine' Exp. 1870 : Atl. St. Setubal B., C. Sagres, 26, 36; 

 Med. 50, Benzert Road, Rasel Amoush. 



Distribution. Mediterranean, Adriatic, Madeira, Canaries ; 20- 

 100 fms. 



Fossil. Pliocene. S. Italy and Rhodes. 



Distinguishable from P. opercularis by its smaller size, more 

 convex or gibbous shape, broader and flattened ribs, and smaller 

 ears, Monterosato altered the specific name to commutatus, because 

 philippii had been used by Michelotti praviously to Recluz for 

 another and a fossil species ; but, as Brugnone has lately pointed 

 out, Michelotti's species belong to Pleuronectia or Amussium. 

 According to Homes, that species is the Pecten duodecimlamellatus 

 of Bronn, which has precedence of Michelotti's name by eight years. 



9. Pecten maximus, Linne. 



Ostrea maxima, L. S. N. p. 1144. 

 P. maximus, B. C. ii. p. 73 ; v. p. 169, pi. xxiv. 

 'Porcupine' Exp. 1870: Atl. St. Vigo B., Tangier B. ; Med. 

 Algesiras B., G. Bona, Benzert Road. Young specimens. 



