738 ADDITIONS TO THE FAUNA OF LORD HOWE ISLAND, 



Etymology: — lafus, wide; spina, spine: the two ventral 

 and the postanal spine being strongly compressed. 



Distribution : — Lord Howe Island. 



Mr. King's collection contains a single specimen, 155 milli- 

 meters in length, of this interesting fish. 



BALISTID^. 



Among the specimens collected for me by Mr. King is a young 

 balistid, 50 millimeters in length, which appears to be allied to 

 Canthidermis macidatus. Giinther* unites all the various forms 

 of Canthidermis under two headings, Balistes maculatus and 

 Balistes aureolus, and in all the forms of B. macidatus, as given 

 by him (with the exception of the one mentioned below), the 

 second dorsal and anal rays are much higher anteriorly, especially 

 in the adult, and this indeed is made a generic character by 

 Bleeker; but in my example, which is of course very young, these 

 tins are regularly convex, the middle rays being the longest, as in 

 Hollard's Balistes brevissimus, which Giinther reduces to a 

 synonym of Canthideimis macidatus. But the main reason which 

 has determined me to refer this species to Canthidermis lies in 

 the absence of the postbranchial shields, which are found in all 

 the other genera with which I am acquainted. That the absence 

 of these shields is not due to the immaturity of the specimen 

 appears to be sufficiently assured by their presence and indeed 

 strong development in a still smaller (.34 millimeters) balistid — 

 1 B. heter acanthus, Bleeker, — from Samoa, which I have examined 

 side by side with the Lord Howe specimen. 



I append a full description of this latter fish, so that if an adult 

 should fall into the hands of anyone conversant with our fishes it 

 may be the more easily recognised. 



1 Canthidermis sp. 

 D. iii, 29. A. 26. 



Body covered with rough granular scales; no caudal spines nor 

 osseous plates behind the gill-openings. Depth of body If, length 



* Catal. Fish. viii. pp. 213-215. 



