1870.] ^"i^ [Cope. 



Measurements, M. 



Greatest length of bone 0.046 



" " dental series 0.026 



Transverse diameter first tootli 008 



" " third tooth 009 



" *' fourth tootli 008 



Width bone at second tooth (exterior) 017 



" " '• " (anterior) 018 



Length proximal limb 02 



From the same locality as the last. Dedicated to Capt. Clirence King, 

 to whom science is indebted for the survey of the fortieth parallel, and 

 the palaeontoJogical discoveries incidental to it. 



Mylocyprinus LOJSfGiDENS. Cope. 

 This third species of the genus is represented by one right pharyngeal 

 bone bearing the upper three teeth. It is quite distinct from the species 

 already named, in several points. The ala commences by an abrupt 

 expansion opposite to the middle of the first tooth, instead of by a gradual 

 widening of the proximal limb. Hence, in this species the latter is more 

 slender than in the others. Next, the teeth are of nearly equal size, the 

 transverse diameter of the three being about equal, though the last is 

 rather flatter than the others. Thirdly, the teeth are more slender, the 

 length of the shanks being much greater than the long diameters of the 

 crowns ; these measurements are nearly equal in the other species. 

 Lastly, the type of the present species is scarcely half the size of the 

 most numerous individuals of the M. rcbustus and M. Mngii. The basis 

 of the tooth series rises obliquely backwards, as in M. robustus, and 

 within it are the bases of two small teeth of the inner row, better devel- 

 oped than in that species. The diameters of the second and third teeth 

 are equal. 



Measurements. M, 



Greatest length right pharyngeal 0.039 



" " tooth series 018 



" " proximal limb 013 



Elevation second tooth 007 



Transverse diameter crown 0048 



"Width bone at crown (exterior) 0. 115 



" " " (anterior) 013 



From Catharine's Creek, Idaho, No. 9192. Capt. King's Expedition. 

 Collected by J. C. Schenk. 



SALMONID^. 



RHABDOFAPJO. Cope. 

 Genus novum. 



Teeth on the maxillary and mandibular arches large, numerous ; teeth 



on the vomer, glossohyal, and palatine bones, also well developed. Teeth 



with hollow crowns and plicate dentine, which is ribbed on the pulp 



cavity, and grooved externally. Muzzle and mandible sub-equal. Max- 



A. p. s. — VOL. XI— 41e 



