76 ACANTHOPTERYGII. 



outer row in the upper jaw somewhat enlarged. Fins — dorsal spines rather strong, the third and fourth the 

 longest, and equal to half the height of the body below, but rather less in the young, interspinous membrane 

 rather deeply notched, the last dorsal spine rather longer than the one preceding it. Pectoral equals the 

 length of the head : second anal spine the longest,* and in the adult a fourth longer than the fifth of the 

 dorsal, it is striated in grooves along its front edge : caudal cut square or slightly emarginate. Colours — 

 silvery, darkest along the back, and in the young with an indistinct darkish band along the middle of the body : 

 a dark spot, having steel blue reflections, exists on the opercle : snout dark : a dark streak along the dorsal 

 fin most distinct in the immature. In a specimen 3-|- inches long the snout is dark, and there is a large 

 black blotch covering 2/3 of the opercle. 



Bleeker considers that P. argyreum is distinct from P. guoraka, the former being distinguished by a 

 more obtuse and more convex profile, by the eyes being considerably larger, and by the second anal spine 

 being weaker and shorter. 



In examining a series of specimens of these fishes, it appears to me that one can hardly separate one 

 species from the other, the difference being probably due to age and perhaps sex. In the young the eye is 1/3 

 the length of the head and only 1/2 a diameter from the end of the snout, and the second anal spine generally 

 only equals the length of the postorbital portion of the head. 



Habitat. — Seas of India to the Malay Archipelago, said to have been captured in fresh water. Russell 

 observed that his fish was 2 feet in length, if it was this species, his specimen must have been a most 

 extraordinarily large one. 



9. Pristipoma operculare, Plate XX, fig. 2. 



Playfair, Fish. Zanz. p. 24, pi. iv, f. 1. 



B. vii, D. ii P. 19, V. 1/5, A. f, C. 17, L. 1. 57, L. r. ff, L. tr. 9/19, Ca3C. pyl. 5. 



Length of head 2/7, of caudal 2/11 to 1/6, height of body 2/7 of the total length. Eyes — diameter 1/5 

 to 2/11 of length of head, If diameters from end of snout, and 1J apart. Snout pointed and somewhat 

 compressed : jaws of equal length. The maxilla reaches to below the posterior nostril. Preopercle emarginate, 

 finely serrated, most coarsely so at its rounded angle. Teeth — in jaws villiform, the outer row being scarcely 

 enlarged. Fins — dorsal spines strong, the fourth the highest, equal to the length of the postorbital portion 

 of the head and higher than the rays. Pectoral as long as the head reaching to above the anal fin : the 

 ventral does not reach to the anal : second anal spine the strongest and longest equal to the third of the 

 dorsal : caudal emarginate. Coecal appendages — very long. Colours — silvery, with a black blotch at the posterior- 

 superior corner of the opercle : upper half of body with numerous black spots, which in some do, in others do 

 not, form undulating bands : a black spot at the base of each dorsal spine and ray : dorsal and caudal dark 

 edged : anal blackish in its front half. 



The young are silvery, with the opercular spot distinct, a black mark in the axilla, and a few dark spots 

 over the base of the pectoral fin : dark spots on the dorsal almost form bands along its upper and lower 

 thirds : a dark band is likewise present along the centre of the soft portion : last half of caudal dark grey. 



The form of this species is very similar to P. nageb, Riippell, which, however, has D. -ri-\sj L. 1. 42-43, 

 and the eye 1/6 of length of head. The second anal spine comparatively longer. In the specimen in Berlin, 

 16 inches long, the spots are sprinkled over one side of the body, but in bands as shown in Riippell's figure 

 on the other. A specimen of P. suillum, C.V. at Berlin from the Cape of Good Hope makes it doubtful whether 

 P. operculare may not prove to be a variety of that species. 



Habitat. — East coast of Africa to Sind, where it is common : attaining at least 15 inches in length. 



Genus, 18 — Hapalogekts, Richards. 



Pogonias, sp. Tern, and Schleg. 



Branchiostegals six or seven : pseudobranchim. Body rather elevated and compressed. Eyes of moderate size. 

 Cleft of mouth horizontal : the anterior and under surfaces of the lower jaiv and the lips covered with fine barbel-form 

 papillm. Preopercle serrated: opercle with short spiines. Villiform teeth in the jaws, vomer, and palatines : an outer 

 row of conical but somewhat obtuse teeth in either jaio, but no canines : tongue smooth. A deepily notched dorsal fin 

 having eleven spines : anal with three : caudal convex or slightly notched. Scales ctenoid, of moderate or small size, 

 and extended over the fins. Air-vessel simple. Pyloric appendages few. 



Geographical distribution. — Seas of Sind to China and Japan. 



The specimen captured off Sind differs from the usual definition of the Genus,f and I am indebted to the 

 kind services of Professor Peters for suggesting its present position. 



* In six specimens in my collection the following are the comparative lengths as regards the second anal spine : 

 1. Total length 3j% inches: of body without caudal fin 2^ inches : 



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t The single species recorded here has seven (not six) branchiostegal rays : its spinous dorsal is very low, and divided by a 

 notch from the soft portion of the fin, making one almost doubt the propriety of including it in this Genus. On the other hand the 

 general form of the body, the dentition, &c. being the same, it is placed as an aberrant form of Hwpalogenys. 



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