FISHES EMBIOTOCOIDAE RHACOCHILUS TOXOTES. 1 89 



the fleshy gums. The mouth is of moderate size, both jaws being even or else the lower lip 

 projecting slightly beyond the upper. The posterior extremity of the maxillary reaches to a 

 vertical line drawn across the eye ball, about midway between the rim of the orbit and the 

 pupil. The opercle is well developed, irregularly rounded exteriorly ; the sub-opercle is small, 

 tapering outwardly and completing the sub-convex edge of the opercular apparatus. The sub- 

 opercle is quite large and stoutish, occupying a prominent place in the apparatus just referred 

 to. The tongue is smooth, sub-pyriform, depressed, pointed anteriorly. The branchiostegals 

 are six on either side, very much flattened and hidden under the opercular apparatus. 



The origin of the dorsal fin corresponds with the posterior margin of the insertion of the 

 pectorals ; there are eleven spinous rays, increasing gradually in height from the first to the 

 eleventh, giving to that portion of the fin a sub-convex outline. The anterior part of the soft 

 portion of that fin rises above all the spines, but diminishes gradually backwards so that its last 

 rays are not higher than the second spinous one. The base over which the articulated rays 

 extend is one-fifth longer than the base of the spinous portion. The articulated rays, twenty- 

 three in number, the last one being double, subdivide but once upon their extend. The anal fin 

 is preceded anteriorly by three spinous rays, the first one of which is the smallest ; the soft 

 portion of the fin resembles, in its outline, the soft portion of the dorsal. Its base, however, is 

 shorter than that of the latter, and while the anterior spine is situated opposite the insertion of 

 the third articulated ray of the dorsal, it yet extends a little further posteriorly. The soft rays, 

 numbering twenty-nine, the last being double and counting as one, are simple as far as the 

 twelfth, the rest subdivide, at first once and posteriorly twice. The caudal is furcated and 

 constitutes a little more than the fifth of the total length ; its rays are highly subdivided. The 

 extremity of the ventrals overlap the vent ; the rays of which it is composed subdivide but 

 twice. The pectorals, broad and elongated, extend a little further back than the ventrals when 

 bent alongside the body ; there is a rudimentary ray upon the upper or external margin of these 

 fins ; the ray next to it is simple and much stouter than the rest, which subdivide three times. 

 Br. VI : VI ; D XI, 23 ; A III, 29 ; C 5, 1, 6, 6, 1, 4 ; V I, 5 ; P 21. 



The scales being well developed, twelve longitudinal series are to be observed upon the 

 anterior portion of the back, above the lateral line, and twenty-one series between the lateral 

 line and the insertion of the ventrals. The lateral line itself is concurrent with the dorsal 

 outline. The scales are a little longer than deep, rounded upon their posterior, upper and lower 

 margins, and truncated anteriorly. They are largest upon the middle of the flanks, very small 

 along a narrow band opposite to the base of the anal fin, with a patch of much larger ones, 

 isolated from the rest and situated a little way above the vent. The base of the caudal is 

 covered with irregular scales which are not observed upon the base of the other fins. The cheeks 

 and opercular apparatus are scaly ; seven rows of scales may be observed between the orbit and 

 the concavity of the preopercle, the convex limb of which is naked, whilst the opercle, sub- 

 opercle, and interopercle are densely invested with scales, ten or eleven vertical series of which 

 exist on the opercle. A dozen of scales constitute the supratympanic patch. The dorsal groove 

 extends from the seventh spinous ray to the thirteenth or fourteenth articulated ones ; the sheath 

 being composed of two rows of scales. 



The ground color is of a uniform olive above ; the sides are silvery with light longitudinal 

 streaks running along the middle of the scales. The upper surface of the head is of a deep 



