586 DR. GWYN JEFFREYS ON THE MOLLUSCA OF THE [Julie 17, 



wegian arctic Exp. 1878, 'Challenger' Exp. (off Fayal); 70-790 

 fms. Var. angusta, 'Challenger' Exp. (off Teneriffe) ; 70 fms. 



Fossil. Miocene and Pliocene. Cassel, Mayence Basin, Italy. 



Recent : L. borealis, Woodward, L. abyssicola, A. Adams, and 

 the very young L. tenuis, Seguenza. Fossil : Peetunculus aradasii, 

 Testa, P. grossi, Aradas, and L. inccquidens, Saudberger. 



1. Malletia obtusa, M. Sars. 



Yoldia abyssicola, M. Sars in Christ. Vid. Selsk. Forh. (1858), 

 p. 86. 



Y. obtusa (M. Sars), G. O. Sars ' On some remarkable Forms of 

 animal Life from the great Deeps off the Norwegian Coast ' (1872), 

 p. 23, pi. 3. f. 16-20. 



'Porcupine' Exp. 1869: St. 19, 22,28, 30. 1870 : Atl. 9, off C. 

 Espichel. The body is clear-white and gelatinous, and the upper 

 tube is very long and cylindrical. 



Distribution. Loffoden Isles to the Bergen coast, Norwegian arctic 

 Exp. 1876 (between Norway and Iceland) ; 200-650 fms. 



The MS. name abyssicola, originally given by the late eminent 

 Professor Sars to this remarkable shell, was afterwards changed by 

 him to obtusa in consequence of Torell having described and figured 

 another shell which Sars regarded as also belonging to Yoldia, under 

 the same name abyssicola. The present species is not the Yoldia 

 obtusa of Gould (1846), from Hong-Kong harbour ; but that shell 

 belongs to the genus Leda ; and at all events it is better to avoid 

 further confusion by appropriating the name obtusa to the North- 

 Atlantic shell. For the reasons which I gave in ' British Con- 

 chology ' (ii. 153), I cannot recognize the genus Yoldia. 



The late Dr. Morch placed this species in the genus Malletia of 

 Desmoulins, from an examination of my specimens. A tribute of 

 respect to his memory is justly due from all conchologists for his 

 bibliographical research, and other valuable labours. 



2. Malletia cuneata, Jeffreys. (Plate XLVI. fig. 10.) 

 M. cuneata, Jeffr. in Ann. & Mag. N. H. Nov. 1876, p. 435. 



' Porcupine ' Exp. 1869 : St. 19, 20, 28. 1870 : Atl. 16, 17, 17a, 

 off C. Espichel, 22 ; Med. 51. 



Distribution. 'Valorous' Exp., Norwegian arctic Exp. 1876; 

 1333-1760 fms. 



3. Malletia excisa, Philippi. 



Nucula excisa, Ph. Moll. Sic. ii. p. 46, t. xv. f. 4. 



M. excisa, Jeffr. in Ann. & Mag. N. H. Nov. 1876, p. 435. 



'Porcupine' Exp. 1869: St. 20, 21, 28. 



Distribution. ' Valorous ' Exp., ' Challenger ' Exp. (W. of Azores 

 and Canaries) ; 1125-1785 fms. 



Fossil. Pliocene. Biot, Calabria, and Sicily. 



It will be seen that the last species, as well as many other deep- 

 water shells which have been noticed in the present paper, are Cala- 

 brian and Sicilian Tertiary fossils. Besides these species, others of the 



