326 CEETACEOUS PELECYPODA 



genus/' says the author, ''agrees with Nucula in the simple pallial line and internal 

 ligament, and with Malletia in not being nacreous or pearly within, and in general 

 form and character. It belongs to a distinct family betw^een nuculinm and 



MALLETINJE,'^' 



It is possible that this is the recent representant of the fossil Ctenodonta, 

 connecting in many respects the Ntjculidm with the Nuculanid^, for in those fossil 

 forms the pallial line has not been shown to be sinuated, but the position of the 

 cartilage or ligament has also not as yet been satisfactorily traced out. 

 ^ 3. Ctenodonta, Salter, 1851, (Decade Geol. Surv., Great Britain, I; Tellinomya, 



Hall, ?ex-parte; see Meek and Worthen, Geol. and Pal., Illinois, iii, p. 308), 

 This name has beea proposed as a substitute for Hall's Tellinomya, but unless 

 y- it ha^been shown that all the species described by Hall as Tellinomya possess the 

 hinge-teeth of the Nuculidm, which I greatly doubt, there is no sufficient reason for 

 identifying both genera. Some of the TellinomycB noted by Hall and M'^C oy certainly 

 are so extremely thin shells that they most improbably belong to the Nucjjlidm, 

 Taking Cten, contracta, Salter, as the type of the genus, it could be characterized as 

 elongately oval, sub-equilateral, smooth, or finely concentrically striated, valves 

 moderately convex, hinge represented by two diverging comb-like denticulated 

 margins without a special hinge area between them and the beak, and below the 

 latter not interrupted by a pit; ligament apparently external, posterior to the beak. 

 Prom Malletia the shells would seem only to differ by a more elongated and more 

 tumid form. 



List of cretaceous species of nuculid.e. 



Among the cretaceous Nuculm there are several somewhat elongated and nearly equilateral 

 forms which appear to resemble Sarepta, but unless the internal structure of these shells has been 

 properly examined no very correct generic determination can be attained. The numerous species 

 from the German Plsener particularly require re-examination. 



For reference of the first 29 species noticed see Pictet and Campiche in Pal. Suisse III"^^ g^j, 

 3^^ part., p. 416 et seq. ' *' 



1.13._i\r. planata,^ Desh., simplex,-\ Desh., suh-tnangida^X Koch and Dunk., ovata, Mant, 

 (non eadem WA^^ov.), gurgitis, P. and Roux, AUmisis, d'Ovh., nmoUeana, V. and U., CarUusi J 

 P. and R., Arduennensis, d^Orb., pecUnata, Sow., Jaccardi, P. and Camp., hivirgata, Eitt/ 

 f onmtissima, d' Orb. ' ' 



The two last named species are referable to the sub-genus Acila. 



14-28.— iV. impressa, (^.Renauxiana, d'Orb.), antiquata, aUusa, apiculata of Sowerby 

 (hnecda, Sow., is a Nuculana), Ramondi, d'Arch., striaMa, Rom., (Nord Kreid p Q% 



n'J^?/l' T- T "■""'"' ^''"•^' ^"'''"■' '^'^'^■' ^»^-^^^'->fe-. cl^Orb., eoncinna, Sow.; 

 (1832)§ Stackei, Zitt., redempta, Zitt., vox, Gieb., (=tenera, Mull.),|| ascendens, Alth,'^ panda, 



* Why does cVOrbigny (Pal. fran?. cret, pi. 300.) represent this and the two other ^ecXe, - Comueliana (accordin.to P 

 andCa.p, only a .anety of ^^„„,.; and «,„^... -on the san,e plate with distinct fulcra? Have these speiesane:t„^i 

 ligament ? or is it only a lapsus penicilU of the artist ? 



t Non simph., A. Ad., 1836, a recent shell, the name of which mast be changed. 



S IN on conemna, A. Ad., 1856, which name must be changed 



a .relt"::x^?^::eTh;tc::: ttxrrnr i' t't " '"' ^^^^^ -'-' '- ''^- ^— ^>- 



„ „., „ ^ •* ""i"^"*^"'. b"t this IS a decidedly slender and more elongated form. 



•I r^de Favre Desc. M. foss. de Lemberg, 1869, p. 119. 



^ /^^' ' V'^ c/.^ 4,»-vnv 4cX)L tAj^ JLtAA^, om) oJl Ma^ 





