314 MR. J. Y. JOHNSON ON TRACHICHTHYS DARWINII. [May 22, 



seventh dorsal spine. They are much longer than the ventral fins, 

 which are inserted under their roots. These fins, which have 

 rounded apices, are supported by a long stout and striated spine and 

 six branching rays. The space between and in front of their roots 

 is flat. The vent is placed a little in advance of the anal fin, about 

 three-fourths of the total length behind the snout. The trapezoidal 

 anal fin commences under the seventh soft ray of the dorsal fin, and 

 terminates at some distance from the base of the caudal fin, a little 

 behind the end of the dorsal. The first of its three stout spines is 

 very short ; and the third, though much longer than the second, is 

 only half as long as the soft portion of the fin is high. The lobes 

 of the deeply forked caudal fin are rounded at the tips, and the 

 membrane between the rays is clothed with rows of small scales. At 

 both the upper and under edges of the tail, and supplementary to the 

 caudal fin, is a series of six glassy spines, which become gradually 

 larger backwards. 



The spines of the fins are striate but not roughened, whilst the 

 exposed sides of the rays are strongly echiuulate. The lateral line 

 is a slightly elevated and oblique ridge on the upper part of the 

 body, not following the curve of the back. It is formed of twenty- 

 seven perforated and rather distant scales, which are somewhat 

 larger than those clothing the body. 



Only a single specimen of this interesting addition to the marine 

 fauna of Madeira has been hitherto obtained. It was taken in the 

 month of April of the present year ; and, from the protruded stomach 

 and inflated membranes about the eyes, it may be inferred that it 

 came from a great depth. I have named it in honour of that ac- 

 complished man of science, Charles Darwin, Esq., to whom natural- 

 ists are greatly indebted, amongst many other labours, for an excel- 

 lent monograph on the Cirripedia. The fishermen from whom I 

 procured the specimen stated that they had never previously seen 

 anything similar ; the name of " Serra do alto," or Sawfish, allu- 

 ding to the ventral keel, was therefore merely an impromptu appel- 

 lation. 



From Hoplostethus mediterraneus, C. & V. (of which I have ob- 

 tained a few specimens at Madeira), it is distinguished generically 

 by the possession of vomerine teeth. Even if it were congeneric 

 with that fish (and some ichthyologists may think that Hoplostethus 

 should not be separated from Trachichthys), several well-marked 

 differences would point it out as a distinct species : e.g., 1, the pos- 

 session of eight spines and fourteen rays in the dorsal fin in place 

 of six spines and thirteen rays, and of three spines and twelve rays 

 in the anal fin in place of three spines and nine or ten rays ; 2, the 

 scaly cheeks ; 3, the absence of a series of oblong cells near the 

 posterior border of the preopercle ; A, the exposure of the whole 

 branchiostegal membrane, which in Hoplostethus is entirely con- 

 cealed by the gill- covers ; 5, the shortness of the pectoral fins, which 

 do not reach, as in Hoplostethus, to the vent. 



With the two known species (both of them Australian) of the 

 genus Trachichthys it agrees in having teeth on the vomer ; but 



