NUCULITES. 107 



whicli lie refers to Goldfuss's species, with some, as it seems to me, very- 

 reasonable doubt.^ 



3. Genus — Nuoulites, Conrad, 1841, 



" Bquivalve ; hinge with cardinal teeth as in Nucula, but apparently uninter- 

 rupted beneath the apex ; an interior rib, like that of Solecurtus, but narrower, 

 'extends from the apex either direct or slightly oblique towards the base, never 

 passing much beyond the middle of the valve." 



Conrad thus defines his genus, remarking that it has " much the exterior aspect 

 of Nucula," but that the deep sinus in the cast gives the same distinction as 

 between Solen and Solecurtus, and that it has no f ossette in the hinge. N. lamellosa, 

 Conrad, is the first of the nine species which be places under it. According to 

 Fischer some of these species belong to Nucula, and some, with a clavicular ridge, 

 to Cleidoioliorus, Hall, 1847. But Hall in 1883-5 appears to have sunk the 

 latter genus, referring such ridged shells to Nuculites, and (inter alia) Cleido- 

 pJiorus ovatus, Sowerby, sp. 



Conrad's generic definition seems perfectly clear and valid, whether or not he 

 has been consistent in the species he has referred to it. 



Cuculhlla, M'Coy, 1851, Adranaria, Munier-Chalmas, 1876, and Gadomia, 

 de Tromelin, 1876, appear to be synonyms. 



1. Nuculites? latissimus, Pliillii)s, sp. ? Plate XII, figs. 11, 11 a, 11 h. 



1841. Nucula latissima, Phillips. Pall. Foss., p. 137, pi. Iviii, fig. 65*. 

 ? 1841. — OVATA, Phillijjs (pars, not Sowerhy). Ibid., p. 39. 



Descrijjtion. — Shell rather small, oval, very convex and transverse. Umbo 

 small, low, rounded, turning rather forward, situated at or about the anterior fifth 

 of the length, and apparently bearing internally a median clavicular process 

 which extends halfway down the back. Hinge-line very long, rather curved, with 

 about four very minute, thin, radiating, central teeth under the umbo, nine large, 

 oblique, strong anterior lateral teeth and about forty short, rather stout, perpen- 

 dicular, parallel posterior lateral teeth. Anterior margin broad, and deeply and 

 evenly convex. Inferior margin long and very slightly convex. Posterior margin 

 much produced, and so deeply convex as to be almost bluntly angular. Contour 

 of back very convex, sinking steeply in front. Surface ornamented by about thirty- 



^ 1895, Beushausen, ' Abhaudl. k. Preuss. Geol. Landes.,' n. s., pt. 17, p. 74, pi. viii, figs. 8—10. 



