102 MOLLU.iCA. 



teeth*, and others, which, with the hinge of tlie Tellinae, have not 

 the plica of the posterior extremity — tliey arc the Tellinidks, 

 Lam.f 



It is necessary to distinguish from the TellinBS, the 



LORIPES. Poll, 



In which the middle teeth of the lenticular shell are almost effaced, 

 and where there is a simple sulcus for the ligament behind the nates. 

 The animal is furnished with a short double tube, and its foot is pro- 

 longed into a kind of cylindrical coi'd. Besides the usual impres- 

 sions, we may observe, on the inside of the shell, a line running ob- 

 liquely from the print of the anterior muscle, which is very long, 

 towards the nates. There is no flexure in the print of the mantle for 

 the retractor muscle of the tube \. 



LuciNA, Brug. 



Separated lateral teeth, as in the Cardia, Cyclades, &c., that pene- 

 trate between the plates of the other valve ; in the middle are two 

 teeth, frequently, but slightly apparent. The shell is orbicular, and 

 without any impression of the retractor muscle of the tube ; that of 

 the anterior constrictor, however, is very long. Possessing similar 

 traits of character with the Loripedes, their animals must be analo- 

 gous §. 



The living species are much less numerous than those that are 

 fossil; the latter are very common in the environs of Paris ||. 



We should approximate to the Lucinae, the Ungulin^ea, which also 

 have an orbicular shell and two cardinal teeth ; the lateral ones, how- 

 ever, are wanting, and the anterior muscular impression is not so 

 long ^. The genus 



Venus, Lin. 



Comprises many Testacea whose general character consists in the 

 teeth and plates of the hinge being approximated under the summit, 

 in a single group. They are usually more flattened and elongated, in 

 a direction parallel to the hinge, than the Cardia. The ribs, when 

 there are any, are almost always parallel to the edges, being directly 

 the reverse of their arrangement in the Cardia. 



The ligament frequently leaves an elliptical impression behind the 

 summits, which has received the appellation of vulva, and before 



* Tell, hyalina, Chemn., VI, xi, 99 ;— Te// vitrea, lb., 101. 



t Tellinides timorensis, Lam. 



X Tellina lactea. 



§ J'enus pennsylvanica, Chemn, VII, xxxvii, 394 — 396, xxxix, 408, 409; — V. 

 ulentula, Id., xl, 427, 429. 



II Lucina saxonim, Lam., Deshayes, Coq. Foss. des Env. de Paris, I, pi. xv., f. 5, 

 6 ; — Luc. grata, Defr. ; Ibid. pi. xvi, f. 5, 6 ; — Luc. concentrica, Lam., Desh., lb., 

 xvi., f. 11,12. 



f Unyulina transversa, Kam., Sowcib., Geu. of Shells, No. X, 



