376 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 10, 



dorsal fin is unfortunately incomplete. There is evidence to prove, 

 how^ever, that it was a continuous fin, the anterior or spiny portion 

 containing not less than ten rays, and the hinder portion at least 

 eleven, probably more (fig. 4) . The interapophysial plates supporting 

 the spines are broad and equidistant, vi\\\\ the exception of the three 

 anterior, which are slender and not bladed. Of these one is unarmed 

 between the occiput and the fin, and the succeeding two contribute 

 to the support of the anterior spine. The osselets bearing the hinder 

 portion of the fin are more closely set. The spines are compressed 

 laterally, having a sharp edge to the front. The third from the 

 front is the longest and strongest, and the second and fourth are 

 recessed to accommodate its expanded base. They are all more or less 

 irregularly grooved or striated in the longitudinal direction. The fin, 

 when fully expanded, had a forward inclination. In many of the 

 preceding details we find a much nearer approach to the dorsal fin of 

 the Scieenoids, and especially to the genus Pristipoma, than to any 

 of the Percoid genera. 



The pectoral fins are nowhere preserved. The ventral fins are 

 thoracic. They consist of one long sharp spine and about eight rays, 

 supported on pelvic bones of considerable size. The coracoids have 

 a roughly corrugated surface, but are devoid of the transverse plate 

 so largely developed in the genus Perca. 



The anal fin is one of a formidable character. It has a short strong 

 fulcral spur at its base, succeeded by a powerful spine of great strength, 

 backed up by a second spine of inferior size. These are succeeded by 

 a few soft rays. The bones giving support to this fin are of corre- 

 sponding strength. The Percoid genus Holocentrum and the Scigenoid 

 Pristipoma are the only examples I am acquainted with having anal 

 fins so powerfully armed. 



The tail had nine principal rays in the upper lobe and eight in the 

 lower. The extremities are deficient. 



The coincidences between the characters of the dorsal fin with the 

 Pristipomes are fully carried out in the other locomotive organs. 



We come now to the most remarkable feature of this fossil, namely 

 the dentition. The dentigerous bones visible are the premaxillary 

 and submaxillary. These are furnished with an outer range of closely 

 set, regular, strong, conical teeth, with sharp recurved points and 

 expanded bases, succeeded by ranks of similarly formed, though 

 smaller teeth. Those of the priiicipal range near the symphysis, 

 although rather larger than the others, do not project as in Dentex, 

 Paffrus, and Lefkrinus ; nor are larger teeth intercalated as in the 

 Serrani. Whether the vomer, palatines, and pterygoids were denti- 

 gerous or not, there is no evidence to determine ; but the branchial 

 arches were decidedly so. In most of the specimens, the osselets 

 composing this apparatus are seen, owing to the absence of the oper- 

 cular flap, and in each case they are confusedly mingled with multi- 

 tudes of conical teeth, of analogous form to those constituting the 

 true dental series. The form of these teeth is not unlike a miniature 

 representation of the canine teeth in XJrsus. 



On comparing the dentition of this curious fish with analogous 



