428 PROCEEDINGS OF THE ACADEMY OF [1881, 



description and figures are drawn from Italian specimens. The 

 form of the Arctic shell recalls the Verticordia Farisiensis of 

 Deshayes, which, however, differs in the presence of a cardinal 

 hinge tooth ; the pallial sinus represented in the figure (vol. i, 

 PI. X, fig. 12) is stated by the French conchologist to have been 

 erroneously placed there by the artist, and, therefore, cannot be 

 taken as a character separating it from L. abijssicola, in which 

 the pallial impression is also non-sinuate (" hele, ikke bagtil 

 indbugtede Kappe linie "). Finally, in the list of deep-sea 

 mollusca dredged in the Bay of Biscay (Annals and Mag. Nat. 

 Hist., October, 1880, p. 316), Mr. Gwyn Jeffreys revives the 

 generic term Verticor'dia for a newly-discovered species, V. 

 insculpta ; is this species likewise to fall under Pecchiolia ? 



The similarity existing between Lea's genus Hijopagus and 

 Crenella^ as exemplified by C. glandula Totten, a relation first 

 pointed out by Jeffreys (Annals and Mag. Nat. Hist., 4th ser., vi, 

 1870, p. '73), is certainly very great, but yet there appear to be 

 suflBcient differences to warrant a generic separation. The 

 umbones in Hippagus are much more prominently developed 

 and spirally twisted, and, as far as I have been enabled to deter- 

 mine, there are no crenulations on the hinge-line ; these, how- 

 ever, may have been eroded in the specimens (Lea's types in the 

 collection of the Academy of Natural Sciences) examined. The 

 structure of the shell appears to have been also considerably 

 heavier than in Crenella. The H. Aemilianits of Stoliczka 

 scarcely appears to differ from the H. isocardidides. 



Note. — While preparing the preceding remarks on the genus Verticordia 

 the author inadvertently overlooked the notice of that genus by Seailes 

 Wood, as contained in his " Monograph of the Eocene Mollusca " (Falteont. 

 Soc. Reports, 1871). Reference is there made to the existence of an ossicle 

 in the hinge, which led Mr. A. Adams to consider the genus as belonging 

 to the AnatinidcB, and, therefore, as distantly removed from the Bucardiidm, 

 with which it had been previously placed by that author. This view is not 

 concurred in by Mr. Wood, who, while in doubt as to its true relationship, 

 places the genus in a family apart by itself — the VerticordidoB (a family 

 name first proposed by Stoliczka). The genus Pe^cMolia is stated to be 

 synonymous with Verticordia, but no grounds are given for so considering it. 



