166 THE VOYAGE OF H.M.S. CHALLENGER. 



Pecchiolia gibbosa, Jeflfreys ; (IG) Pecchiolia angnlata, Jeffreys ; (17) PecchioUa tornata, 

 Jeffreys; (18) Pecchiolia simiosa, Jeffreys. 



Of these Nos. 2 and 3 appear to be identical, and Nos. 5 and 6 also constitute but 

 one and the same species ; but whether or not No. 4 belongs to the same species at 

 present I am vmcertain ; but that Verticordia multicostata, A. Adams, is not the same 

 as Verticordia granidata, Seguenza, as stated by Jeffreys, I feel fully convinced if 

 any reliance is to be placed upon the figures of the latter species in the Journal de 

 Conchyliologie. The form of the Japanese shell is different, and the ribs twenty-six in 

 number, or six more than mentioned by Seguenza. His specimen, however, may have 

 been imperfect, which would account for the difference of outline. 



The following species have been assigned to this genus, but in my opinion they 

 belong to LyonsieUa, namely, — Pecchiolia insculpta, Jeffreys ; Pecchiolia siibquadrata, 

 Jeffreys ; Pecchiolia ahi/ssicola, Sars ; and LyonsieUa gemma, Verrill. 



All of them have the hinge-line in both valves destitute of teeth, and the ligament 

 internal, and in two instances it is stated to be supported by an ossicle. Although in 

 the case of LyonsieUa gemma this is not mentioned, there seems to be every probability 

 of its being present. Jeffreys does not describe the hinge of his Pecchiolia inscidpta, but 

 having had an opportunity recently of examining the type, I find it corresponds with that 

 of LyonsieUa in every respect. 



Verticordia ornata (d'Orbigny), var. 



Trigonulina ornata, d'Orbigny, in Sagra's Hist, de Cuba, vol. ii. p. 292, pi. xxvii. figs. 30-3.3. 

 Trigoniluna oi-nata, Chenu, Man. de Conch., vol. ii. p. 169, fig. 8-13. 

 Verticordia ornata, Pischer, Journ. Conch., 1862, vol. x. p. 380. 

 Verticordia ornata, Dall, Bidl. Mus. Comp. Zool., vol. ix., No. 2, p. 105. 



Habitat. — Station 33, off Bermuda, in 435 fathoms ; coral mud. 



Two right and one left valves from this locality differ slightly in form and in the 

 greater number and more slender character of the ribs. These are twelve in number, two 

 of them on the hinder dorsal slope, being separated from the rest by a broad unribbed 

 space. The ventral margin is somewhat angular at the middle, curved upward in front 

 and obliquely truncate behind, forming with the arcuate dorsal margin a rather acute 

 extremity. The cardinal tooth of the right valve is very strong and prominent, and the 

 posterior dorsal edge is vevj deeply grooved for the reception of the margin of the left 

 valves, in which the margin of the lunule is much thickened, forming a sort of tooth, 

 which fits into a pit in front of the denticle in the other valve. The ligament is in a 

 groove under the dorsal margin behind the umbones, and is supported in both valves by 

 a distinct ridge. The distribution of this species is very remarkable, it having been 

 recorded from the West Atlantic, California, and the China Seas. 



