704 DR. GWYN JEFFREYS ON THE MOLLUSCA OF THE [June 7, 



and A. obloncjus of Monterosato. Specimens dredged in the Swedish 

 arctic Expedition of 1868, from 550 fathoms, are of a very large 

 size. This corroborates Mr. Norman's statement, in his ' Notes on the 

 Oceanic Copepoda ' (Nares's 'Arctic Voyage'), viz.:— " "With respect 

 to size, we find here, as in many other instances among the Inver- 

 tebrata, an extraordinary development of the Arctic specimens, which 

 are at least six times the size of those from the Irish coast." 



i/ 8. AxiNUs suBOVATUs\ Jcifrcys. (Plate LXI. fig. 8.) 



Shell triangularly oval or wedge-shaped, nearly equilateral, 

 rather convex, extremely thin, glossj^ and semitransparent : sculp- 

 ture none : colour whitish : margins sloping from the beak towards 

 each end, somewhat truncate and angular on the anterior side, 

 rounded on the posterior side, and gently curved in front : beaks 

 small, prominent, recurved : lunule long and narrow, defined by a 

 slightly raised ledge on both its sides : ligament narrow, somewhat 

 projecting : hinge-line obtuse-angled : hinge-plate very narrow ; 

 teeth none, except a small point at the inner edge of the hinge-plate 

 on the anterior side : inside polished : scars inconspicuous. L. 0'05, 

 B. 0-075. 



'Porcupine' Exp. 1869, St. 16, 30, 58. 



Distribution. Bay of Biscay ('Travailleur' Exp.), 1300-1408 fms. 



Differs from A. ferruginosus in its wedge-shaped appearance. 



<^ 9. AxiNus CYCLADius, S. V. Wood. 



Kellia cycladia, S. V. Wood, Crag Moll. (Biv.), p. 122, t. xi. 

 f. A,a,b: B. C. ii. p. 228; v. p. 179, pi. xxxii. f. 3. 



'Porcupine' Exp. 1869: St. 19. 1870 : Atlantic, 30. 



Bisti-ibution. 'Valorous' Exp., Norway arctic Exp., Shetland, 

 Falmouth and Lisbon telegraph-cable, Mediterranean, and ^gean : 

 30-1750 fms. 



Fossil. Pliocene : Coralline Crag. 



Variety Kellia orbicularis, S. V. "Wood, which is certainly not 

 Scacchia ovata of Philippi, as Mr. "Wood doubtfully supposes. 



/I. DiPLODONTA ROTUNDATA, MoutagU. 



Tellina rotundata, Mont. Test. Brit. p. 71, t. 2. f. 3. 



B. rotundaia, B. C. ii. p. 254, pi. v. f . 7 ; v. p. 180, pi. xxxiii. 

 f. 4, 4a. 



'Porcupine' Exp. 1869: St. Galway B. 1870: Atl. C. Sagres; 

 Med., Cartagena B., off Jijeli, Benzert Road, Basel Amoush, Adven- 

 ture Bank. 



Distribution. British coasts to JEgean, Adriatic, Canaries, and 

 Madeira ; 0-60 fms. 



Fossil. Miocene and Upper Tertiaries : Coralline and Red Crag, 

 Belgium, S.W. France, Vienna Basin, Styria, Switzerland, Portugal, 

 Italy, Greece, Rhodes, Cyprus, and Madeira. Post-tertiary : Ca- 

 labria. 



' Somewhat oval. 



