Dr. Kaup on a new species of Fish. 67 



PERISTETHUS RIEFFELI, Kaup. 



Thorns on the front, not on the eye-margins ; parts of the fork 

 broader, and convergent towards the end. The breadth of the head 

 is to the length as 1 : If. The height of the head not quite half 

 the breadth. The thorn-shaped prolongation of the preopercle not 

 comparable with those of P. cataphractus and P. orientalis. The 

 eyes are proportionately smaller, the front narrower and more con- 

 cave, than in P. cataphractus and P. orientalis. 



When we compare its head with those of the other species, we 

 are led to believe that such a head belongs to a larger fish, which, 

 however, is not the case. Our fish is scarcely larger than a large 

 individual of P. cataphractus. In one cavity of the eye of a dry 

 example I found a piece of China paper with the written characters 

 of the country. From that, and the maceration and the varnish, I 

 believe that this example came in an insect-box from China ; it is, 

 judging by the short rays of the first dorsal, a female. 



I have named this very interesting species in honour of the me- 

 mory of my true and excellent friend Dr. Rieffel, who has done so 

 much for our Museum and University. 



Besides these smaller species of Peristethus, there appear to be 

 two mentioned by older authors, which attain an immense size. The 

 first I call 



PERISTETHUS GIGAS. 



Length 3 feet, of which the head is one-third. 



In Valentyn, ' Oud en nieuw Ostindien,' torn. iii. p. 363, fig. 55, 

 is a fish mentioned and figured under the name Tkan Scythan Merah 

 (Red Devil Fish), which belongs, according to Cuvier, to this genus. 



A bad plate of this is also given in Renard's ' Poissons et Ecre- 

 visses,' fig. 67. What makes me doubt whether Renard copied the 

 engraving of Valentyn, is that on the surface of the fork are cavities 

 covered with membranes, which we do not see in the figure of 

 Valentyn. Therefore I believe that both authors used one and the 

 same painting belonging to another collection, made at Amboyna. 



These cavities on the upper side of the bifurcated snout, which we 

 find in the better known species on the under side, permit us to 

 hazard two conjectures. Either this species has these cavities on 

 both sides of the fork, or, by the mistake of the first artist, the 

 cavities of the under side are erroneously placed on the upper side. 



According to Renard, this fish reaches the length of 8 feet 7 inches ; 

 but this does not agree with the assertion of Valentyn. According 

 to the latter, the flesh of this fish is dry and without flavour ; Renard 

 says it is similar to that of the Sturgeon. The last opinion is cer- 

 tainly not founded on experience, but on the analogy of this fish with 

 the Sturgeon. I have more confidence in old Valentyn than Renard, 

 and consequently think that the size of 8 feet is an exaggeration, 

 and that the length given by Valentyn is the more exact. 



Another species, not yet rediscovered, 



PERISTETHUS BREVIFURCATUS, 



is figured, according to Cuvier and Valenciennes, in Cornelius v. 



5* 



