86 rafinesque's 



I. Family, LINGULARIA. Shell equivalve, longitudinal, 

 inequilateral, valves entire, not perforated, 1. G. Lingula of 

 Brugiere. 



II. Family TEREBRARIA. Shell inequivalve, one valve per- 

 forated or emarginated. 



1st Section, Ilacrilia. Shell longitudinal. 



2 G. DicLiSMA, Raf Equilateral, the two valves split at the 

 summit. 



3 G. Apleurotis, Raf 1819. Inequilateral, the great valve per- 

 forate, and with a lateral wing, 



4 G. Trigorima, Raf Equilateral, smaller valve perforate, four 

 cavities- at the base separated by three septa. 



6 G. Obovites, Raf Equilateral, the great valve perforate. 



6 G. Magas (Sowerby) equilateral, great valve with an angular 

 opening. 



2d Section, Idlia. Shell equilateral, nearly equital or hardly 

 transversal. 



"7 G. Terebratula (Brugiere) great valve perforate. 



8 G. Spinifer (Sowerby) subequital, great valve with an angular 

 opening, hinge with two spiral appendages. 



9 G. GoNOTREMA; Raf Shell subtransversal, small valve with 

 aa angular opening, and interval cavity, hinge short, straight or 

 curved. 



3d Section, Platilia. Shell equilateral, transversal or very 

 broad. 

 [8] 



10 G. Platilites, Raf Small valve with an angular opening and 

 internal cavity, hinge very long, often longer than the shell which is 

 thus winged. 



11 G. Pleurinia, Raf Differ from last by the great valve per- 

 forate, shell winged also. 



12 G. Pachiloma, Raf Inequilateral, with thick edges, hinge 

 with a linear opening. 



13 Strophomenes, Raf. Equilateral, hinge broad, great valve 

 notched by a lunulate sinus receiving a lunulate projection of the 

 smaller valve. 



III. Family ATREMOSIA. Shell inequivalve, valves entire, not 

 perforated. 



