FISHES—EMBIOTOCOIDAljJ—RHACOCHILUS TOXOTES. 
189 
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. YI: YI; 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 
