18SI.] ' lightning' AND 'porcupine' EXPEDITIONS. 931 



ened by a rib on the upper part of the posterior side; the whole sur- 

 face is covered with minute prickly tubercles arranged lengthwise in 

 numerous rows : colour yellowish-white : epidermis inconspicuous : 

 7n(n-ffins in front slightly curved, fibrous at the edges : beaks trian- 

 gular, somewhat incurved ; umbones prominent : hinc/e-plate thick : 

 inside of a silvery lustre. L. (about) 0*5, B. (about) 0"8. 



'Porcupine' Exp. 1869: St. 23a. 1870: Atl. 27-29. Frag- 

 ments only. 



Distribution. Palermo {Monterosato) ; 65 fnis. (120 m.). 



>/■ 1. Pecchiolia ABYSSICOLA, M. Sars. 



Lyonsiella ahyssicola, M. Sars, Vid.-Selsk. Forh. 1868, p. 257. 



P.abyssicola, G. O. Sars, 'On some remarkable Forms of Animal 

 Life from the great deeps of the Norwegian coast,' i. p, 25, pi. iii. 

 f. 21-43 ; Moll. Reg. arct. Norv. p. 82, t. 20. f. 5, a-d. 



'Porcupine' Exp. 1869: St. 1, 6, 23ff, 39. 1870: Atl. 16, 17, 

 17«. 



Distribution. Spitzbergeu to the Skagerack, ' Valorous ' Exp.j 

 Davis Strait, New England ; 50-1450 fms. 



Body yellowish, streaked with pink at the sides : mantle thick : 

 tubes sessile ; the larger tube is wide and exposes the gills, and it is 

 fringed with a few short orange-colour tentacular cirri; the smaller 

 or excretal tube (which is situate at the broader end of the shell) is 

 circular : foot conical and white, protruded at the narrower end of 

 the shell. 



I feel myself compelled by the laws of scientific nomenclature to 

 use the generic term PecchioUa instead of Verticordia. The latter 

 name was proposed in 1844 by Mr. Searles Wood for a Crag shell 

 which was figured by Mr. James Sowerby in his ' INIineral Conclio- 

 logy' (plate 639); but, in consequence of the publication of the 

 second volume of Philippi's work on the Mollusca of the two Sicilies 

 in the same year (1844), Mr. Wood and Mr. Sowerby gave up Ver- 

 ticordia and adopted Hippar/us, under the supposition, which they 

 shared with Philippi, that their fossil shell belonged to Lea's genus 

 Hippagus. However, I have elsewhere shown, and it is quite cleai-, 

 that the last-named genus is the same as Crenella, and referable to 

 another division of the Conchifera. Whether the author of the name 

 Verticordia had a right to repudiate it and erroneously substitute 

 another for it may be questionable. Verticordia had been long 

 previously established by de Candolle for a genus of IMyrtaccoe, and 

 is now commonly used by botanists. PecchioUa was proposed in 

 1851 by Meneghini for a well-known ]\liocene shell, the Gkcana 

 argentea of Mariti, 1797 = C arietina, Brocchi, 1814. In PeccMolia 

 the beak is incurved as in Isocardia, leaving a more or less deep 

 lunule, which is impressed on the hinge, and gives the appearance 

 of a tooth-like projection in some species. But I am by no means 

 satisfied that PecchioUa is distinguishable from Lyonsia by any 

 sufficient character. 



60* 



