176 Dr. Richardson's Contributions to 



Dimensions {continued). inches, lines. 



Length from upper lip to anus 2 8^ 



ventrals 2 2 



dorsal 1 9 \ 



tip of gill-cover 1 7\ 



centre of eye 1 



Diameter of orbit 6 



Length of caudal lobe Ill 



central caudal rays 1 



Depth of caudal fork 9 



Length of pectorals 1 3 



ventrals 10 



Height of eighth dorsal spine 9J 



first and thirteenth ditto 5^ 



anterior soft rays 8^ 



third anal spine 9 



seventh and anterior soft rays 7£ 



body 2 5 



: trunk of tail 5 



Length of trunk of tail 7| 



Acanthurus grammoptilus (Nob.), The Lurgee. 



No. 13. Mr. Gilbert's list. 



This Acanthurus is named e Lurgee ' by the natives of Port 

 Essington, and is very abundant in the bays near the head 

 of the harbour. It appears to have a greater affinity with 

 the Ac. matoides than with any other species described in 

 the ( Histoire des Poissons ;' but as matoides is said to have 

 filiform tips to the ventrals and caudal as well as a pointed 

 dorsal and anal, I am induced to keep them distinct, though 

 I am unable to say how far it is correct to do so, having seen 

 neither figure nor specimen of matoides. Ac. nigro-fuscus 

 (Forsk.), which resembles the Port Essington fish in colour, 

 has the profile slightly curved in the form of the Italian /. 

 The Lurgee has the pale ring round the base of the caudal 

 which exists in Ac. Blochii, and seems to agree with that 

 species in some other characters; but the caudal spine, though 

 it is not remarkably large, can scarcely be said to be little. 



The profile is fully as convex as that of the mata of Russell (82), 

 but the body is more elongated, being less high at the pectorals. 

 The height of the body is equal to half the length of the oval, com- 

 prised between the tip of the snout and base of the caudal lancet. 

 The dorsal is less high and more angular behind than that of the 

 mata ; but the anal and caudal are as represented in Russell's figure. 

 When the latter fin is fully spread out in the Lurgee, the tapering 

 falcate tips project about a fourth part beyond the straight interme- 

 diate edge ; when only partially displayed, the edge of the membrane 

 is lunate, and the upper tip of the caudal is just perceptibly longer 

 than the under one. The tapering ventrals are acute, but their points 

 are not filiform. Each jaw contains eighteen or nineteen teeth, the 

 upper ones, and the central pair of under ones, being crenated on 

 their sides and rounded tips ; while the lateral ones of the lower jaw 



