483 



much rougher on the head than on the body, especially 

 around the lips and on the throat, where they become tuber- 

 cular; the body-scutes are ornamented with rows of granules 

 radiating from a central point. About three distinct scutes 

 are present behind the dorsal and anal fins; caudal peduncle 

 otherwise naked. 



Colour. — Creamy-white in formaline, with more or less 

 numerous blackish spots and lines distributed as follows: — 

 Naked parts with a varying number of narrow black lines; 

 some large black spots on and around the bases of the body- 

 spines, which become smaller as they recede from them ; the 

 greater part of the back is also spotted in one example. 



Described from four specimens, 86-113 mm. long. The 

 example figured is 100 mm. in length, and is selected as the 

 type. 



Loc. — Doubtful Island Bay, South-western Australia,. 

 20-25 fathoms; between Cape Naturaliste and Geraldton,. 

 Western Australia. 



Aracana, Gray. 



Ostracion, subgenus Aracana, Gray: Ann. Mag. Nat. Hist., 

 i., 1838, p. 110; Giinther : Cat. Fish. Brit. Mus., viii., 1870, 

 p. 266. 



Platycanthus, Swainson : Nat. Hist. Classif. Fishes, ii., 1839, 

 pp. 194, 324 (P. auratus, Shaw). 



Acerana, Kaup. : Arch, fiir Naturg., xxi., 1855, p. 219 

 (misprint). 



Carapace with five more or less distinct ridges — two supra- 

 lateral, two infralateral, and an abdominal. A supraorbital 

 and two supralateral spines on each side; a mediolateral, and 

 one to four infralateral spines are more or less developed, 

 Caudal peduncle with broad saddle-shaped scutes, which may 

 form an osseous ring around the base of the tail. Dorsal with 

 9-11, anal with 10-11 rays. 



Type. — According to Giinther (loc. cit., p. 267), the name 

 Aracana was first used by Gray in his "Illustrations of Indian 

 Zoology," published about 1829, for a fish which he figured 

 as A. aurita, Richardson. He later considered that his figure 

 represented a distinct species, which he called A . reevesii, and 

 which must therefore be accepted as the type of the genus. 

 Unfortunately Gray's figure is not available to us, so we rely 

 upon Giinther in the above statement. 



The species of Aracana are subject to considerable varia- 

 tion in form, development of the spines, ornamentation of the 

 scutes, and colour-markings. We have examined a series of 

 twenty-five specimens of different sizes from various locali- 

 ties, and find them to be separable into several groups; but 

 which of these groups represent species, subspecies, sexual 

 q2 



