42G PROCEEDINGS OF THE ACADEMY OF [1881. 



shell, would seem to be in the family Bucardiidae, the animal 

 differing from Bucardia {Isocardia) cor in the posterior [mantle] 

 opening being fringed." The shell of this species, Mr. Adams 

 further adds, is very different from that of V. novemcostnta 

 Adams and Reeve, from the China Sea, and very similar to the 

 V. gramdata of Segnenza, a Tertiary Sicilian fossil. Whether 

 this last is a true Verticordia I am not in a position to judge, 

 not having seen anj^ specimens, but if the figures illustrating 

 Seguenza's descriptions be correctly^ executed, they appear to 

 represent a species of fossil very different from the Vei^iicordia 

 cardiiformis of Wood, the typical species of the genus Verti- 

 cordia. The same may be said of Seguenza's figure of V. acuti- 

 costata^ the species described by Philippi from the newer Ter- 

 tiaries of Calabria, and which was considered by Wood, as 

 identical with the species from the English Crag ; the absence of 

 a lunule (very prominent in Verticordia), the prominently 

 recurved spiral umbones, and the great ventricosity of the shell, 

 would seem to indicate a form much more nearly allied to 

 Pecchiolia. If, however, as Segnenza states {loc. cit., p. 293), 

 " les valves des individus jeunes de cette espece (d'un diametre de 

 4 a 8 millimetres) sont minces, phis circulaires, moins renflees,et 

 s'accordent parfaitement avec la figure de M. Philippi ..." the 

 question is settled as far as the identity of the Sicilian and 

 Calabrian fossils is concerned, and a strong relationship between 

 the genera Verticordia and Pecchiolia would be indicated ; but it 

 is at the same time very singular, and what makes it appear 

 somewhat suspicious, that in the second species stated by 

 Segnenza to belong to the genus Verticordia — V. gramdata — 

 there should be considerable differences in the character of the 

 hinge, and, moreover, a deep lunule (" lunula profunda, cordata, 

 ecostata, granulis carens ") should be present. An indubitable 

 species of Verticordia, the V. JEmmonsii Com:, has been described 

 from the Miocene deposits of North Carolina ; the V. Parisiensis 

 Deshayes, from the Paris basin, is at best but very doubtful. 

 Although Verticordia. and Pecchiolia may be very closely related 

 forms (and their positions, everything considered, if the observa- 

 tions of Mr. Adams on V. Japonica be correct, would be about 

 as near to Isocardia as to any other recent genus), there does not 

 appear to be as yet sufficient evidence for uniting the two genera, 

 as has been done by some conchologists. V. gramdata and V. 



