72 ACANTHOPTERTGII. 



Genus, 16 — Helotes, Cm. 



Branc7doi>tegals six. Eyes of moderate size. Cleft of mouth rather smaZZ, jaws nearli/ equal in front. 

 Preojierde serrated ; operele ivith weak spines. The outer row of teeth in the jaws having a small lohe on each side : 

 palate edentidoiis. Dorsal fin single, not deeply notched, having twelve spines ; anal with three. Scales small, ctenoid. 

 Air-vessel divided by a constriction into an anterior and posterior portion. Pyloric ajipendages in moderate numbers. 



Geographical distribution. — Ceylon* ? to the Malay Archipelago and beyond. 



Sixth group — PristipomatidsB. 



Branchiostegals from five to seven. Preopercle serrated or entire. Mouth moderately protractile. 

 Teeth in the jaws. Three anal spines. Air-vessel destitute of any constriction. 



Genus, 17 — Peistipoma, Cuv. 



Genyfremus, Genyatremus, Anisotremus and Pristocantharus, Gill : Htrmulopsis, Steind. 



Branchiostegals seven : pseudobranehicB. Body oblong, compressed. Eyes of moderate size. Cleft of raouth 

 horizontal : gape not very wide : premaxillaries moderately protusible : jaws of nearly equal length : a central 

 longitudinal and deep groove below the symphysis of the loieer jaw, and two small open pores under the chin : n» 

 barbels. Preopercle serrated : operele with indistinct points. Teeth in the jaws villiform without canines : palate 

 edentulous. Dorsal with from eleven to fourteen spines, and sometimes having a deep notch between the last two : 

 anal with three spines. Vertical fins scaleless or only so along their bases. Scales ctenoid and of moderate or small 

 size, piresent on the head, including the preorbital and lower jaw. Air-vessel simpile, destitute of any constriction. 

 Pyloric appendages few. 



Geographical distribution. — All tropical seas and likewise found in the Mediterranean : the young of the 

 Indian species are often taken in backwaters. 



Uses. — Fair as food but not much esteemed : the air-vessel in some places collected as isinglass. Many 

 breed about April or May. 



SYNOPSIS OF SPECIES. 



1. Pristipoma stridens, D. Ts-^rE^ -A-- !> L- i"- VcJW- Purp'^*^^ ^"^ ^he hack, becoming white on the 

 abdomen. Three golden bauds along the body and a dark mark on the upper third of the operele. Red Sea, 

 along the Meckran coast to Sind. 



2. Pristipoma olivaceum, D. if, A. -^, L. r. |-f . Olive-grey, the head glossed with purple : a black 

 mark on the operele. Beloochistan and Sind. 



3. Pristipoma furcatum, D. ^Vs'^ -A-- tV' ^- ^- 55-60. Silvery, with six sinuous blackish-brown bands, 

 three of which are above the lateral-line : a dark mark on the operele : spinous dorsal with three rows of brown 

 spots and a dark edge : upper half of dorsal dark, and a band along the anal. Seas of India to the Malay 

 Archijjelago. 



4. Pristipoma hasta, D. tsJj-j, A. y'!^, L. 1. 4-5-60. Four or five lines of dark grey along the sides, 

 sometimes coalescing and forming bands : two or three rows of spots along the dorsal fin. Red Sea, East coast 

 of Africa, seas of India to the Malay Archipelago and beyond. 



5. Pristipoma Commersonii, D. -fi, A. f, L. 1. 60. Sinuous rows of black dots over upper two-thirds of 

 body, and several rows along the dorsal fin. Madras. 



6. Pristipoma macv.latum, D. ittS-tT' ^- f •> ^- 1- 52-56. Greyish, becoming white beneath : a black 

 band over the nape, and six black blotches along the side, three above and three below the lateral-line, not 

 forming bands but placed like squares on a chess board. Red Sea, East coast of Africa, through the seas of 

 India to the Malay Archipelago and beyond. 



7. Pristipoma Dassumieri, D. -LJ, A. f , L. L 50-54. Greyish, becoming lighter below : two golden 

 lateral bands : fins with dark edges. Seas of India. 



8. Pristipoma guoraka, D. yll-ff, A. y?-g-, L. 1. 4:5-47. Silvery, an olive spot on the operele. Seas of 

 India to the Malay Archipelago. 



9. Pristipoma operculare, D. W, A. f , L. 1. 57. Silvery, with a black blotch at the posterior-superior 

 angle of the operele : upper half of the body with numerous black spots, sometimes forming undulating bands ; 

 a dark spot at the base of each dorsal spine and ray. East coast of Africa to Sind. 



1. Pristipoma stridens, Plate XVIII, fig. 8. 



Scicena stridens, Forsk. p. 50. 

 Perca, stridens, Bl. Schn. p. 87. 

 Pristipoma simmena, Cuv. and Val. v, p. 260. 



Pristipoma stridens, Riippell, N. W. Fisehe, p. 122, t. 31, f. 1; Giinther, Catal. i, p. 300; Klunzinger, 

 Fische Roth. Meeres, Verb. z. b. Ges. Wien, p. 732. 



* In the list of the Acanlhopterrpian fishes of Ceylon, prepared by Dr. Giinther (Sir E. Tennent's Nat. Hist, of Ceylon, 1861, 

 p. 360), is Helotes polytwnia Bleeker, as tliat species = Thcrapon quadrilineatus, I conclude that Dr. Giinthcr's species, which 1 have 

 not seen, may be identical. 



