38 Fossil F hes 



middling size. Head rather small, presenting a finely granu- 

 lated surface resembling Bhagreen. Back but slightly arched. 

 Pectoral fins middling. Ventral small, inserted midway be- 

 tween pectoral and anal. Anal large. Dorsal middling, situ- 

 ated opposite the posterior part of the anal. Tail forked, equi- 

 lobed.* Scale* extending a little upon the base of the upper 

 lobe. All the fins have a series of raylets inserted obliquely 

 upon the first or anterior ray, producing a serrated or denticu- 

 late appearance. In this species these raylets are very fine 

 and close, presenting a strong contrast with those of the ]'</- 

 taoniet us fultiu, where they are so long and stout as to render 

 the term serrate inapt. The succeeding rays have an articulate 

 appearance, nnd are finely subdivided toward their extremities. 

 The following list of the number of rays in each fin may serve 

 to give an iil< a of their relative size : 



Pectoral, lame and strong, 10 to 12. 



Ventral, - - - about 8. 



Dorsal, ----- 10 to 1 2. 



Anal, ----- 20 to 30. 



< audal, - - - - - 30 to 40. 

 A remarkably perfect specimen of this species, from the same 

 locality, is now in possession of the Yale .Natural History So- 

 ciety, al .New Haven, and is represented in Plate I.t 



[nthe arrangement of Agassiz, the fish described above would 

 be comprehended in the order Ganmdesy and family Lepir 

 doides. h- equilobed tail would assign il to the second di- 

 vision of the family, the Homoccrci, as he has termed them. 

 Prom seven fusiform genen w arranged in this division ii is 



'l i. indeed is not *i ctly the case. Its structure, hov analogous to 



th.it of il,.' Si mttuiatii.' , r;mk( il by Agassiz among the Homocerci, and diffeia most 

 (rum (bal of the trne Heteroeerd, when i lie scales, ami proliably the 

 id in ll o point "i the upper lobe. 



1 wiih that '" ;i ty ia ;i specie* oi P 

 ■ P. fulfils, bnl from the other numerous apt 

 oft).: orm and proportions, and which I have ventured to name, 



from ii,i. poet '•../'/.' SoeP t< U 



