1881.] NATURAL SCIENCES OF PHILADELPHIA. 42T 



acuticostata {et conseq., V. cardiiformis for Gwyn Jeffreys) are 

 stated to be also living forms, both inhabiting the Japanese seas, 

 and the former also the Mediterranean (Gwjai Jeffrys, " Mediter- 

 ranean Mollusca," Annals and Mag. of Nat. Hist., 4th ser., vi, 

 18T0, p. 73 ; " Japanese Marine Shells and Fishes," Journal 

 Linnean Society, Zoology, xii, 1874, p. 101 ; Jour. Linn. Soc, 

 xiv, 18T9, p. 420) ; these species are all classed by Mr. Jeffreys 

 as PecchioHa, and placed among the Gorhulidse^ and if the deter- 

 minations have been correctly made, they go far to confirm the 

 observations of Seguenza as to the variability of the genus 

 Verticordia (and of its passage into Pecchiolia). But in addition 

 to these forms of so-called Pecchiolia^ we have the P. [^LyonHiella] 

 abyssicola of M. Sars (Selsk. Forh., 1868, p. 257 ; G. 0. 

 Sars, " On some remarkable Forms of Animal Life," 1872, i, p. 

 25; Zoological Record, 1872, p. 166; G. 0. Sars, Bidrag til 

 Kundskaben om Norges Arktiske Fauna, 1878, p. 108, PI. 20, 

 fig. 5), an Arctic form certainly verj'^ distinct in tlie totality of 

 its characters from at least some, if not all, of the preceding, but 

 which is nevertheless admitted by Mr. Jeffrej's into the genus 

 Pecchiolia, and placed alongside two new species of his own 

 description, P. gibbosa and P. tornata (Annals and Mag. Nat. 

 Hist., 4th ser., xviii, 1876, p. 494). It certainly scarcely appears 

 possible that three such very distinct forms (at least as they appear 

 to me) as are represented b}^ the Ghama arietina of Brocchi 

 {Pecchiolia argentea Meneg.), Verticordia cardiiformis ofWood, 

 and Lyonsiella abyssicola of Sars, can belong to the same genus. 

 The shell of this last is said to be thin, pellucid, inequivalve, and 

 gaping posteriori}^, whereas in G. arietina it is comparatively 

 thiciv, equivalve, and completely closed. Nor does Sars' descrip- 

 tion of the animal of his species at all accord with Adams' 

 observations on Verticordia Japonica. In the former the foot is 

 said to be long, subcj'lindrical, and provided with a bj'ssus, 

 whereas in the latter it was found to be " small, triangular, and 

 compressed." Again, in the former, the siphons are separate, 

 subsessile, with the brancliial not prominent (anal prominent), 

 whereas in V. Japonica the " sessile siphoual orifices " are " close 

 together, the branchial larger than the anal." The supposed 

 pallia! sinus stated to exist in Ghama arietina by Pecchioli, was 

 probably founded on an imperfection in the shell, since the 

 pallial impression is stated to be simple by Homes, whose 



