178 Mr. F. M'Coy on the Irish species of Cephaloptera. 



broadly falcate, recurved, and without any fin-like margin on 

 the anterior edge. The appendage to the head forms a semicy- 

 lindi'ical process in the P. Giorna, but forms two horn-like fins, 

 one on each side of the head, in the Irish fish and in Fabroni^s 

 Mediterranean one ; these are represented in the figure sent to 

 Lacepede and engraved in his work, with I think rather too many 

 turns, being twisted into regular conical horns ; the correspond- 

 ing parts in the specimen under consideration show also a strong 

 tendency to roll spirally, but not amounting to more than I have 

 represented in the sketch ; this is however a matter easily exag- 

 gerated by an artist, or the difference of age and sex would very 

 probably make a difference in the length and consequent inroU- 

 ment of those parts. 



Dr. Fabroni's species is defined as a " falciformly dilated 

 brown ray, whitish beneath,^^ &c. ; this colouring agrees exactly 

 with our specimen, but difi'ers entirely from that of the P. Giorna : 

 another point of agreement between the two former specimens is 

 the extreme slenderness of the tail, it not being more than half 

 the thickness of that of the P. Giorna ; the tail in both speci- 

 mens of the P. Fabroniana is defective as to all that portion from 

 the barbed spine to the tip, so that the exact position or form of 

 the spine is unknown. The figure given by Lacepede is of the 

 under-side only ; it agrees however very well in the general form 

 and proportions, broad, recurved pectoral fins, frontal processes, 

 and the small size of the tail. 



There is a very strong resemblance also between the present 

 fish and the Indian Cephalopte7'a Kuhlii (Valenc.) as figured by 

 Miiller and Henle in their ' Systematische Beschreibung der Pla- 

 giostomen,^ &c., as may be perceived by comparing the sketch I 

 have given with their drawing, particularly in the form of the 

 lateral processes of the head and the general proportions of the 

 body ; but our specimen and Dr. Fabroni^s seem to differ from 

 that species in the small size of the head and some minor points, 

 in addition to the difference of habitat. 



Length (of the Irish specimen) from the front to the dorsal 

 fin 1 foot 8 inches ; entire width 3 feet 8^ inches ; height of 

 dorsal fin 2| inches, length the same ; from one eye to the other 

 8 inches. 



Cambridge, 12th January 1847. 



