65 



anterior end, beneath \vliicli tlie hitter is narrowly rounded. The beaks 

 being nearly terminal, the anterior portion of the shell is very short, 

 and the posterior much elongated. Apart from the irregularity caused 

 by. the beaks, the general outline is almost that of a -pnve ovoid, the 

 height being rather greater in front than behind. 



The sui-face is marked by rather coarse and unequal concentric stria? 

 of growth, bat the sculpture is much eroded. Judging by the im- 

 pressions .on a broken cast, the hinge teeth seem to have been of the 

 same number and shape as those of the preceding species. 



Length of the most perfect specimen, one inch ; height, in the middle, 

 nine lines ; maximum thickness, five and a half lines. 



A single example, with the test imperfectly preserved on one valve, 

 and a fragment of the cast of another. 



This little shell appears to have some distant analogies with the 

 Callista tenuis of Hall and Meek, * and with the Venus sublcevis of 

 Sowerby, f but the generic position of the present fossil is so uncertain 

 that it would be a waste of time to speculate uj^on its 8j)ecific relations 

 Avith such iipperfect materials at hand for comparison. It is just as 

 likely to be a Tapes or an oval Cyprimeria as a Callista. 



Besides the two Callistce ju.Ht described, there are a few large casts in a 

 very poor state of preservation. Judging only by external form, some 

 of these at least may have belonged to the Veneridse, although no indi- 

 cations of the pallial sinus characteristic of that family as opposed to 

 the Glossidse, can be traced in any of them. The most perfect specimen, 

 which measures two ai'id a half inches in length by two inches in height, 

 has much the general shape of Cyprina ovata of Meek and Hayden, I 

 but that sjjecies has a less swollen umbonal region, and its test is com- 

 jxiratively thick. That of the Queen Charlotte Island shell is extremely 

 thin and fragile. 



» 



Unio Hubbardi, Gabb. 



Plate IX, figure 1,3. 



Unio Huhhardi, Gabb. " Palteontology of California," Vol. II, pages 190-91, Plate 

 XXX., fig. 85. 



* '• Memoirs of the American Academy of Arts and Sciences, Cambridge," Vol. V. New Series 

 Plate I., fig. 5. "Report on the Invertebrate Cretaceous and Tertiary Fossils of tlie Upper Missouri 

 Country," Sec, page 188, Plate V., figs. 1, a to d. 



t "Transactions of the Geological Society of London." Series IV. Vol. II., page 342, PJate XVII 

 fig. 5. 



J " Proceedings of the Academy of Natural Sciences, PhiLadelphia, 1857 " page 144. " Report on 

 the Invertebrate Cretaceous and Tertiary Fossils of the Upper Missouri Country," &c., pao-e 146 Wood 

 cut especially. -^ > i- o ^■m 



