90 ACANTHOPTERYGII. 



1. Dentex rivulatus. 



Riipp. N. W. Fische, p. 116, t. 29, fig. 2 ; Giinther, Catal. i, p. 372. 

 Gymnocranius rivulatus, Khinz. Verb. z. b. Ges. Wien, 1870, p. 765. 



D. fa P. 15, V. 1/5, A. T %, C. 17, L. 1. 48, L. tr. 7/20. 



Length of head 4/17, of caudal 2/11, height of body 3/10 of the total length. Eyes — diameter 3/11 of 

 the length of head, If diameters from the end of snout, and 1J apart. The depth of the preorbital rather exceeds 

 the length of the diameter of the orbit. The maxilla reaches to below the front nostril. Hind limb of preoperele 

 almost vertical and entire, a few serrations exist along its rounded angle. Teeth — an outer row of strong' canines 

 in the upper jaw, and a strong lateral row of conical ones : lower jaw with six canines hi front and a lateral 

 conical row which posteriorly become rather obtuse. Fins — dorsal spines rather strong, increasing in length 

 to the fourth from whence they decrease to the last, the height of the fourth equals the distance from the eye to 

 the end of the preorbital bone, the last dorsal spine equals the length of the third and is slightly longer than the 

 ninth : second anal spine two-thirds as long as the third which equals the length of the post-orbital portion of 

 the head : caudal deeply forked. Scales — five rows on the cheeks : superiorly they do not extend so far as to 

 opposite the posterior edge of the orbit. Colours — greenish, glossed with golden on the sides : wavey blue lines 

 along the snout and over the preorbital. 



Habitat. — Red Sea and Ceylon. 



Genus, 23 — Synagris (Klein) Giinther. 



Dentex, pt. Cuv. and Val : Nemipterus, Swains. : Spondyliosoma, sp. Cantor : Heterognathon, pt. Steind. : 

 Dentex (C. V.) Bleeker.* 



Branchiostegals five or six : pseudobranchice. Body oblong, rather elongate and a little elevated. Eyes of 

 medium or rather large size. Mouth moderately protractile, its cleft more or less horizontal : jaws of about equal 

 length. Preoperele entire or feebly serrated : opercle without any or with a not very prominent spine: the distance 

 between the eye and the angle of the mouth considerable.^ Moderately sized curved canines in the upper and generally 

 feeble ones in the front of the lower jaw : an inner villiform band in either jaw and usually an outer conical row: 

 vomer, palate, and tongue edentulous. One scaleless dorsal fin having ten spines and nine rays : anal also scaleless 

 having three spines arid seven rays : all the spines weak : caudal forked. Scales ctenoid, of moderate size, three rows 

 on the preoperele none along its outer border, on the snout, preorbital, or jaws. Air-vessel not constricted but notched 

 posteriorly. Pyloric appendages few. 



Swainson's genus Nemipterus is founded on Dentex filamentosus, C. and V. = D. striatus = Synagris, 

 Giinther, and consequently might perhaps (to prevent further confusion) be employed instead of Synagris. 



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

 beyond. 



SYNOPSIS OF SPECIES. 



1. Synagris striatus, D. V"; A. f-, L. 1. 48. Preoperele serrated : only 2 rows of teeth in the lower jaw, 

 no conical ones. Two first dorsal rays and upper lobe of caudal prolonged. Silvery, with purplish bands. Seas 

 of India to Surinam. 



2. Synagris tolu, ~D. l -f, A. -f-, L. 1. 48. Preoperele entire. Lateral conical teeth in either jaw. Dorsal 

 spines elongated and interspinous membrane deeply notched. Roseate, with yellow longitudinal bands. Seas 

 of India to the Malay Archipelago. 



3. Synagris Bleekeri, D. y, A. f-, L. 1. 48. Preoperele entire. No outer conical row in the upper jaw, 

 a single conical lateral row in the mandible. No elongated spines or rays : interspinous membrane slightly 

 notched. A spot on the opercle. Seas of India. 



4. Synagris filamentosus, D. y, A. f, L. 1. 48. Preoperele serrated. A lateral outer row of small conical 

 teeth in the upper jaw only. Upper caudal lobe prolonged : interspinous membrane slightly notched. Yellowish- 

 red, with roseate longitudinal bands. Seas of India. 



5. Synagris notatus, D. y, A. f, L. 1. 47. Preoperele entire. An outer row of small conical teeth in 

 the upper jaw, also a similar row in the mandible, but becoming very small in the last fourth of the jaw. No 

 elongated spines or rays ; interspinous membrane slightly notched. A brilliant spot on the first 5 scales below 

 the lateral-line. Andamans. 



1. Synagris striatus, Plate VIII, fig. 5. J 



? Coryphama striata, Bl. Mss. 



? Goryphaina lutea, Bl. Schn. p. 297, t. Iviii. 



Dentex striatus, (? Cuv. and Val. vi, p. 252) ; Jerdon, M. J. L. and Sc. 1851, p. 134. 



* Genus Synagris (Klein) Bleeker = Dentex (C. V.) Giinther in part, and is not similar to Synagris, Giinther. 



t The preorbital in the following species of this genus is high and consists of two pieces, the posterior of which ends in a 

 point at its posterior-superior angle, but this point, which is of varying extent, does not form a spine as in the genus Scolopsis. The 

 posterior border of this preorbital plate is free, the skin covering it not passing directly on to the cheeks, but being first reflected on to 

 the posterior surface of the plate. 



J Marked Synagris luteus on the plate. 



