the Ichthyology of Australia. 29 



Cuvier considers this fish to be the same with the Chatodon 

 punctatus of Linnaeus, and also with the Latte of Russell (No. 

 69). Parkinson's pencil sketch above quoted represents the 

 spinous part of the dorsal as lower, and the articulated part 

 as higher than Russell's figure. And on comparing it with 

 plate 179 in the c Histoire des Poissons,' the mouth appears 

 a little larger, the profile of the nape less gibbous, and the 

 first jointed rays of the dorsal higher, rendering that part of 

 the fin more even anteriorly, though it is equally rounded 

 posteriorly with Cuvier's figure. The anal is also higher an- 

 teriorly and is rounded throughout, and a few radiating 

 lines are indicated on the limb of the preoperculum. In all 

 other respects the resemblance between Parkinson's sketch 

 and the plate in the * Histoire des Poissons' is close. In this 

 work the species is said to frequent the Malabar coast and 

 the seas of Java, New Guinea, and China. 



Chelmon marginalis (Nob.), the Willemawillum. 



No. 12. Mr. Gilbert's collection. 



Only two species of Chelmon are described in the ' Histoire 

 des Poissons,' and these are very readily distinguished from 

 each other by the relative length of their beaks and the form 

 and extent of the spinous part of their dorsals, as well as by 

 the very different patterns of colour they exhibit. Mr. Gil- 

 bert's fish so closely resembles the best known species, the 

 Chelmon rostratus, in general form as well as in part of its 

 markings, that I have some hesitation in proposing it as a 

 distinct species on the strength merely of the characters of a 

 single individual. It wants two vertical bands on the body 

 which rostratus possesses, and the anal fin is decidedly more 

 angular than the dorsal, which is rounded, the reverse being 

 the case in rostratus. There is also a submarginal dark band 

 round the soft part of these two fins in the proposed species, 

 which is not noted in the descriptions or shown in the figures 

 of rostratus. Mr. Gilbert states that his fish is the 'willema- 

 willum' of the aborigines, and that it frequents shallow rocky 

 places and sandy beaches in all the bays of Port Essington. 

 The faculty of shooting a drop of water from the mouth so as 

 to strike an insect, which the members of this genus possess 

 in common with the Toocotes, is, I have reason to believe, en- 

 joyed also by an undescribed New Holland Holocanthus, which 

 greatly resembles Chelmon in the prolongation of the snout. 



The proportions of the Port Essington Chelmon are almost the same 

 with those of the common rostratus. The snout, measured from the 

 nostrils, is exactly one-sixth of the total length, caudal included ; 

 which again is double the height of the body. The anal fin forms 



