318 RECORDS OF THE AUSTRALIAN MUSKUM. 



sides are continuous with the lower margins of the tail, which is 

 quadrangular, though a fifth ridge is sometimes indicated on the 

 hack near the base of the dorsal tin. Head moderate, varying from 

 less than half to two-thirds the length of the trunk. Snout short 

 and thick, equal to or more than one-third the head, and with a 

 very strong median ridge above; from this, two other ridges pass 

 backwards over and behind the eyes, while there is a fourth 

 median one on the occiput. A small blunt spine on the side of 

 the snout in front of the eye. Operculum with a distinct trans- 

 verse ridge. The length of the head and body as compared with 

 the tail is very variable, it equalling in some examples one-third, 

 and in others nearly one-half of that member. Branched or 

 simple tentacles may be distributed more or less abundantly over 

 the head, body and tail, or they may be altogether absent. 



Pectoral and dorsal fins well developed, the latter commencing 

 on the seventh segment behind the vent and extending over the 

 three following. Caudal and anal fins present, but minute. 



General colour, greenish with darker and lighter spots and 

 cross-bands. 



Obtt. — Most of the discrepancies between this description and 

 that of Castlenau may be accounted for by the great variation 

 in the characters of the species. Tn his measurements of the 

 snout, however, he writes that it is "contained once and a half 

 in the diameter of the eye." This should be once and a half as 

 long as the eye. Of the operculum also he says that it is " almost 

 carinated," whereas really it has a very distinct ridge. 



/lab. — Twelve specimens collected by Mr. Dene Fry far up 

 Middle Harbour, Port Jackson, where they are common in the 

 sea-grass Zoslera. They agree perfectly with three others in 

 the collection received from Castlenau, taken at Melbourne. 



ICHTIIYOCAMPUS FILUM, Gunther. 



(Plate xc, tig. 1). 



Ichthyocampns Mum, Gunther, Brit. Mus. Cat. Fish., viii., 1870, 

 p. 178. 



D. 14; Body-rings, 13-14 ; Tail-rings, 46-47. 



Form elongate and slender ; body with seven very obscure 

 ridges, tail with four, those on the sides continuous with the lower 

 margins of the tail. 1 lead very short, equal to about two-fifths 

 of the distance between it and the \ent. Snout turned upwards, 

 one-third the length of the head. Operculum without a trans- 



