APPENDIX. 415 



on a yellowish brown ground ; head and fins the same, the latter with yel- 

 lowish lines; belly dirty white, having on each side a row of white dots, 

 corresponding with the lateral line ; head beneath white, freckled with 

 brown, — 11 Feb., 1817. 



DACTYLOPTERUS occidentalis. 



Porsal fins two^ approximate ; the first of four con- 

 nected rays ; the second of eighty of which the 

 seventh is alone forked ; anal fin of six simple rays. 



Inhabits the West Indian seas, St. Vincent. L. Guilding. 

 Total length of the specimen, 6 inches. 



The general characters of this species are much the same as that found 

 in the Mediterranean, and described by Cuvier and Valenciennes ; it 

 differs, however, in the structure of the dorsal rays, having one le.«s in the 

 first dorsal fin, and only the seventh (instead of the sixth and seventh) ray 

 of the second fin forked. All the anal rays are simple, whereas, in the 

 Mediterranean species (according to Cuvier), the fifth is forked. Cuvier 

 has reckoned the two detached rays placed before the commencement of 

 the first dorsal fin as part of that fin ; but this seems to be an improper 

 view of the subject, for these rays are totally distinct from the true dorsal 

 fin, to which they are not united, even at their base, by any vestige of a 

 membrane ; they are, in fact, filiform appendages, perfectly analogous to 

 those before the pectoral fin ; they are soft, very flexible, and fringed with 

 a delicate narrow membrane, which unites them only at their base ; the 

 tip of the pectoral fin, which just reaches the base of the lateral caudal 

 rays, is exactly three fifths the length of the entire fish ; but in the D. 

 voh'ians, Cuvier says, the proportion of this fin is that of two thirds 

 the entire length. I regret not having a specimen of the Mediterra- 

 nean species to compare with this ; for however common it may be in cer- 

 tain localities, I never met with it on the Sicilian or Maltese coasts. The 

 ventis not, as in D. volitans, "precis^ment un milieu'de tout le poisson," but 

 is half an inch nearer to the snout than to the tip of the tail. There is a 

 peculiarity in the pectoral fins in this fish which deserves notice • instead 

 of being inserted in such a way as to be open vertically, and parallel with 

 the sides of the body, as in ordinary fishes, they are so placed as to open 

 horizontally, so that the upper surface corresponds with that which would 

 be the inner in ordinary fishes, and neither of the surfaces can be brought 

 into contact with the sides of the body. Now this remarkable structure, 

 ■which seems to have been hitherto overlooked, is doubtless intended to pre- 

 vent the delicate membrane which unites the pectoral rays from coming 

 into contact with the rough scales of the body; for these scales are so 

 prickly that they would very soon tear and destroy thepectoral membrane, 

 if the fin was placed in the ordinary direction. 



Having only seen a preserved specimen of this species, it will be impos- 

 sible to describe the natural colours. The back appears dark olive, marbled 

 transversely with darker shades ; these shades are more distinct, and assume 

 the form of bands across the head ; the broadest band is between the eyes ; 

 and, behind this, there are five others, gradually diminishing in size, the 

 last being just before the tip of the surscapular spines. 



DACTYLOPTERUS Blochii. 



First dorsal fin of six connected rays ; anal fin of 

 eleven rays ; dorsal fins very wide apart. 



Trigla volitans. Bloch, pi. 351. 



Bloch, when describing his T. volitans, observes that the 



