NO. 1109. PROCEEDINGS OF THE NATIONAL MUSEUM. 301 



which the genera were based agree in hinge structure, in character of 

 sculpture, especially in early stages of growth, in form of the lunule 

 and escutcheon, and in the presence of an umbonal ridge with an accom- 

 panying furrow which produces an emargination of the posterior end. 

 Their chief differences are the external form — subtriangular in the one 

 and elongate subquadrate in the other — and the fact that in Stearnsia 

 robbinsi the free margins of the valves are smooth, while in Remondia 

 fureata they are crenulate within, but in both these respects there is 

 an equal amount of variation in the genus Crassatella. 

 The genus may be redefined as follows: 



Family CEASSATELLITID^. 



Genus REMONDIA, Gabb. 

 (Plate XXVI, figs. 1-8.) 



Shell rather compressed, equi valve or nearly so, elongate subquad- 

 rate to subtriangular in outline; lunule and escutcheon well marked 

 and deeply excavated; ligament partly internal; hinge witli three car- 

 dinal teeth and an anterior lateral lamina in the right valve and two 

 cardinals with a posterior lateral lamina in the left; free margins 

 smooth or crenulate within; sculpture consisting of strong concentric 

 ridges and furrows which may become obsolete in later stages of growth ; 

 Ijosterior end usu.illy (always!) emarginate. 



Type. — Eemondia fureata, Gabb. Other examples : Remondia ferrissi^ 

 Oragin, Stearnsia robbinsi, White, and possibly J.s<arfe bronnii, Krauss,^ 

 Astarte sinuata, d'Orbiguy, and A. carinata, d'Orbigny. 



Note. — The specimens of Remondia robbinsi figured are No. 20137, 

 United States Ifational Museum Catalogue of Invertebrate Fossils. 

 Those of R. fureata are in the collection of the Academy of Natural 

 Sciences of Philadelphia. 



EXPLANATION OF PLATE. 



Plate XXVI. 



Remondia f areata, Gabb. 



Page. 



Fig. 1. Fragment showing the nmbonal portion of a right valve 



2. Hinge of same. (This is the hinge figured by Gabb in Paleontology of 



California, II, pi. 36, fig. 17a) 



3, 4. Two views of GabVs other figured type 



5. Hinge of left valve from a specimen in the type lot 299 



Remondia robbinsi (White). 



6,7. Twt) views of one of the types (from the original drawings published 



by White) 



8. Hinge of left valve of another specimen (from the original drawing of 



a type) 300 



' I have not had access to the description and figures of this species. 



