FAMILY, I— PERCID^E. 77 



SYNOPSIS OF INDIVIDUAL SPECIES. 



1. Hapalogenys Petersi, D. ft, A. £., L. 1. 100. Colours dark slatey, with the fins nearly black. Sind. 



1. Hapalogenys Petersi, Plate XX, fig. 3. 



B. vii, D. ft, P. 19, V. 1/5, A. t V, C. 17, L. 1. ca. 100. 



Length of head 2/7, of caudal nearly 1/6, height of body 4/13 of the total length. Eyes— diameter 2/7 of 

 length of head, rather above 1 diameter from end of snout, and 3/4 of a diameter apart. Dorsal profile much 

 more convex than that of the abdomen, a considerable rise from snout to the base of the dorsal fin, with a shallow 

 concavity over the forehead. Lower jaw somewhat the longer, the maxilla reaches to below the hind third of the 

 orbit. _ Vertical limb of preopercle somewhat emarginate and finely serrated in its whole extent, but the 

 serrations are concealed by the scales : preorbital, sub- and inter-opercles entire. Two very obtuse spines on 

 opercle. Lips thick, they, the chin, and under surface of lower jaw with innumerable closely-set fine papilla, 

 having barbel-like prolongations, but without any groove or deep pores. Teeth — villiform ones in jaws, vomer, and 

 palate, the upper jaw with an outer row of from twenty to thirty conical ones, of no great size, and a similar row 

 but of lesser number in the lower jaw. Fins — dorsal spines of moderate strength, very low in proportion to the 

 rays, they increase in height to the third which equals three-fourths of the diameter of the eye in length, those 

 posterior to it gradually decrease in length to the last but one, the last being higher and its length equal to 

 three-fourths of that of the third spine : interspinous membrane deeply notched : soft portion of the fin highest 

 anteriorly where the rays equal the length of the postorbital portion of the head, whereas the last only equals the 

 height of the third dorsal spine : the pectoral equals the length of the head excluding the snout : the ventral 

 reaches a little more than hah way to the base of the anal : third anal spine much longer and stronger than the 

 second, its length equal to the highest in the dorsal fin, soft portion of the fin similar to that of the soft dorsal : 

 caudal emarginate. Scales — small, finely ctenoid, and covering all the fins. Colours — blackish-grey with the 

 fins darker. 



Habitat. — Sind and Meckran coast, being termed Bah-ri, at Grwadur. Although the species was not 

 uncommon the specimens were so large, I was unable to bring away more than the skin of the smallest one. 

 18 inches in length, which was preserved in spirit, and from which the figure was taken. 



Genus, 19 — Diagrahma, Guv. 

 Plectorhynchus, pt. Lacep. 



Branchiostegals six or seven : pseudobranchire. Body oblong, compressed, vrith tlie upper profile of the head 

 parabolic. Eyes _ of moderate size. Mouth small, slightly protractile : lips thick and folded bach. Preopercle 

 serrated : sub-orbitals entire. Four or six open pores on the under surf ace of the lower jaw but no median groove. 

 Teeth in jaws villiform, without canines : palate edentulous. One dorsal fin more or less receivable into a groove along 

 its base, having from nine to fourteen spines : anal with three. Caudal not forked. Scales ctenoid, usually small, 

 but of a moderate size in some species, present on the head excluding the lower jaw, and usually continued on to the soft 

 dorsal and anal fins. Air-vessel simple, destitute of amj constriction. Pyloric appendages few. 



Geographical distribution. — From the Red Sea and East coast of Africa, through the seas of India to the 

 Malay Archipelago and beyond. These fishes are much more abundant off Sind and as far as Bombay, than they 

 are down the Malabar or Coromandel coasts of India. In fact Russell does not figure one of the genus. 



Uses — generally not in much esteem as food, but some are good eating. 



The species forming this genus are subject to considerable variations in the number of the dorsal rays, 

 whilst a spine* more or less may exist. Irrespective of the differences observable in the dorsal fin, the colour 

 varies almost as widely as amongst the Serrani (see page 9, ante). The ground colour is usually white or yellow 

 in those which are striped longitudinally : there are, as a rule, component parts of two very distinct bands, the 

 upper commencing above the eye by a wide base including the second dorsal spine and ending in a wedge- 

 shaped form along the soft dorsal, both the roots of this band and its terminal extremities may be composed 

 of several narrow ones which coalesce : next there is a central broad one going from the eye to the middle of 

 the caudal fin, also terminating in a wedge-shaped form, this broad band may be made up of two parallel narrow 

 ones, _ separated by an interspace : below this central band may be a lower or third one, either single or 

 constituted of one or more narrow ones. If this is the correct solution of the composition of the ornamental 

 colouring of these fishes, it seems by no means unlikely that some of those now recognised as species, will have 

 to be considered as varieties. The form of the caudal fin often varies considerably in the same species, and this 

 does not appear to be simply due to a^e. 



SYNOPSIS OF SPECIES. 



1. Biagramma crassispinum, D. -^J^g, A. f. Black, tail and edges of dorsal and anal fins white in the 

 immature. Seas of India to the Malay Archipelago and beyond. 



2. Bia/jramma lineatum, D. £-§■:■§•*, A. f-. Yellowish- white with about six longitudinal chestnut bands, 

 which may be reduced by amalgamation into three broad ones : anterior dorsal spines not much higher than the 

 others. Red Sea, seas of India to the Malay Archipelago and beyond. 



* Regarding the dorsal spines "in fact the height of these spines appear to vary very much, and I rally believe that D. 

 balteatum is a variety of D. pictv/m."— Gunther, Catal. i, p. 328. If therefore the number of spines and rays likewise vary, and the 

 colours are subject to considerable modifications, great caution becomes necessary to prevent falling into the error of considering a 

 variety as a distinct species. 



