vertebree, and that the dorsal fin commences about an inch behind the 

 line of the posterior border of the cranium. It also exhibits the strong 

 sculpture of the surfaces of the latter to consist of narrow inosculating 

 ridges, inclosing larger and smaller pit-areas. 



The specimen exhibits this sculpture to be very marked ou the oper- 

 cular, suborbital, parietal, frontal, aud sublingual boues, the only oues 

 ■where it displays the surface. The branchiostegal radii uumber twelve, 

 the upper large and wide. The subopercular is turned up anteriorly as 

 in A. calva, aud is thickened on the border of the suture with the inter- 

 operculum. The sublingual bone has much the form of that of A. calva, 

 but is rather wider and there more abruptly contracted than in a speci- 

 men of the latter before me. The orbit is smaller relatively than in A. 

 calva.. 



It is uncertain whether this aud the preceding species possessed the 

 dentition of Amia or FaiiiyicMliys^ Cope, as the mandibular bone is i)ar- 

 tially broken away on the inner side. Some of the teeth are of small 

 size and abruptly contracted near the apex, so they may belong to the 

 inner row of the true Amia, which is wanting in PappicMJiys. 



The fourth specimen displays the ventral fins and the characteristic 

 femoral supports. The fins originate about an inch behind the line of 

 origin of the dorsal fin in a specimen of 0™.055 depth of body. The 

 scales exhibit also the dermal margin with truncate posterior outline 

 seen in the existing species ; this character is chiefly seen on the abdomi- 

 nal surfaces. There are thirty-five vertebras between vertical lines 

 drawn from the beginning of the dorsal flu and end of the basis of the 

 anal fin ; aud thirty-two dorsal radii in the same interval ; anal radii, 

 nine ; veutrals, six. 



Measurements. 



M. 



Depth of body to vertebrse (No. 1) -.- 0.045 



Length of four dorsal vertebraa (No. 1) 019 



Depth of one dorsal vertebra (No. ]) 010 



Length of head to free border of operculum (No. 2) 124 



Depth of operculum 032 



Length of head on vertex 093 



Length from end of muzzle to orbit 032 



Length of orbit 012 



Amyzon pandatum, sp. nov. — Form very stout ; the body deeper in 

 relation to its length than in the known si^ecies of Amyzon : greatest 

 depth just in front of dorsal-fin, and two-fifths the length to basis of 

 caudal. Length of head oue-third the latter. Spiues of premaxillary 

 causing a protuberance above the end of the muzzle, as in many existing 

 Catostomi. Mouth slightly inferior -, end of muzzle obliquely truncate 

 in profile. Dorsal fin elongate elevated in front; radii mostly short; 

 caudal openly emarginate ; anal not very elongate in either direction ; 

 veutrals below first rays of the dorsal. Eadii, D., Ill, 31 ; A., II, 11. 



Scales, "'' , with concentric and radiating lines well developed. Yer- 

 tebrse, 6, 17, 10. 



Measure7nents. 



M. 



Total length 0.112 



Length to basis of caudal 093 



Length to basis of anal (axial) 071 



Length to basis of ventral (axial) , 041 



Depth of caudal peduncle 015 



Depth of anterior anal rays 022 



Depth at occipital crest 030 



