568 MR. J. W. DAVIS ON A NEW SPECIES OF COCCODUS. 



figured in the Transactions of the Koyal Dublin Society (1887, 

 pi. XXX. fig. 1). In the species now described an equivalent of this 

 spinous process does not appear, unless the posterior extension of 

 the scapular arch could be so construed. The posterior basal exten- 

 sion of the dorsal spine is also very different in the two forms. The 

 dentition of this specimen is not exposed, and the size of the body is 

 only about one-third that of Coccodus armatus, Pictet. The dorsal 

 fin in C. armatus is separated from the occipital region by a distance 

 equal to the length of the head : but in this smaller specimen it is 

 comparatively near, and was, compared with the size of the fish, a 

 larger fin. 



The imperfection of the specimen at the disposal of Professor 

 Pictet led him to the conclusion that the fish presented the most 

 marked analogy with some of the Siluroids, indicating more parti- 

 cularly Syjiodontis, locally termed " Schal,^' which is found in the 

 Nile, and Fimelodus, also found in the Nile, but more abundantly in 

 the rivers of South America. These fishes are protected by dermal 

 coverings on the head, and possess pectoral and dorsal spines ; but 

 in Synodontis the mouth is small, and is armed only with weak, 

 though long, pointed teeth ; and the jaws of Fimelodus are edentu- 

 lous. The arrangement of the fins, as shown in the specimen now 

 described, is quite different from that of the Siluroids named above ; 

 in the latter the dorsal fin is attached to the spine ; in Coccodus it is 

 widely separated from it ; and the anal is shorter and not of the form 

 of that in Coccodus. The great resemblance of the teeth of Coccodus 

 to those of the Pycnodonts, and the cartilaginous character of the 

 vertebrae, indicate a relationship with the Ganoids ; but its exact 

 location in that group must still remain problematical. 



I have pleasure in appending the name of my friend Professor G. 

 Lindstrom, to whom I have been in many ways indebted, to 

 designate specifically the fish now described. 



EXPLANATION OF PLATE XXIL 



Fig. 1. Coccodus Lindstroemi, Dayis. OutHne; natural size. 

 2. The same ; enlarged two diameters. 



Or., orbit; Mx., maxilla; Fmx., premaxilla; Mw,, mandible; Pop., 

 preoperculum ; Op., operculum ; Sop., suboperculum ; Sc, scapu- 

 lar arch ; Fr., frontal. 



