208 RECOEDS OF THE AUSTRALIAN MUSEUM. 



EUCHILOMYCTERUS, gPAl. 710V. 



The single specimen, regarded as the type of a new genus, differs 

 from the descriptions of all described species of Chiloniycterus, by 

 having the anterior dorsal and a temporal spine four-rooted. 

 Owing to the indifferent condition of the specimen, the nature of 

 the nasal tentacles (if present) cannot now be determined ; the 

 presence of a spine in the middle of the forehead would indicate 

 a nearer subgeneric affinity to Cyclichthys than to Chilomycterus. 

 As far as ascertainable, therefore, the new genus may be charac- 

 terised as follows : — Body broad, compressed?. Dermal spines very 

 short, immovable, mostly with three roots, the anterior dorsal, 

 and a temporal spine, with four roots ; all roots (excepting those 

 of the temporal one) overlap, forming a coat of mail. Caudal 

 practically without pedicel; fins small; jaws without median suture. 



EUCHILOMYCTERUS QUADRADICATUS, SJ). nOV. 



D. 12. A. 10. p. 17. C. 9. 



Length of head 2 '8, of caudal fin 3"7 in the total length, 

 interocular space flat and broad, the distance between the middle 

 supraocular spines equal to the length of the head, eyes large, 

 lateral, not quite so long as the snout. The dorsal spines are very 

 low, little more than tubercles: eight or nine between the eye and 

 the tail, those on the sides and belly are scarcely larger, excepting 

 the posterior ones which do not however attain to 3 mm. in 

 length ; the two lateral spines behind the dorsal fin throw their 

 inner roots together on the median line, and behind them is a 

 pair of roots bearing a minute median spine. With this exception, 

 and those below noticed, all the .spines are three rooted, the 

 anterior root covering the lower lateral one of the spine in 

 advance of it. All the roots form strong butres.ses against the 

 spine. Three supraorbital spines, the anterior of which sends its 

 inner root across the forehead, and projected between them is the 

 anterior root of a minute median spine. From this point, back- 

 wards, to between the gill openings, the spines have four roots 

 arranged longitudinally and transversely. A four-rooted spine 

 (the temporal) exists between the the third supraocular and the 

 large three-rooted spine situated above the gill opening ; it is of 

 regular shape, and its roots scarcely touch those of any other 

 spine. The coloration cannot be given, as the specimen is dry 

 and faded. Total length 180 mm. 



I have not figured this species because its most striking features 

 have already been sufficiently expressed and the specimen is not 

 in suitable condition for delineation. It was forwarded to us by 

 Mrs. Nichols in January last. Apart from the peculiarities 

 mentioned, it seems to have some resemblance to Chilomycterus 

 tigrinus, Ouvier. 



