Page:The Zoologist, 1st series, vol 1 (1843).djvu/135

Rh and broad, wreathed as a cable, and thickly set on each ridge with minute sharp spines, which point towards the tail, and are bifurcate at their extremities. The upper pectoral fin is 9 lines in length, and rounded. The ventral fin is united to the anal, the union being marked by an indenture in the membrane: the latter passes under the tail in the same manner as the dorsal, and its rays are armed in the same way. The ventral fin is six-rayed. The tail is short, free and rounded, its rays are divided at about a third of their length, and then subdivided, each terminating in eight delicate rays, which are rough like

Details of Muller's Top-knot. a. Portion of the under side, showing the termination of the dorsal and anal fins beneath the caudal. b. One of the fin-rays magnified, c. Spines of fin-ray. d. Upper pectoral fin, natural size. e. Lower pectoral fin, natural size.

the others. The mouth is nearly vertical, forming an angle of about 9 or 10 degrees. Mr. Yarrell observes that it is small, but in my specimen it is capable of being extended to one inch by three quarters: the teeth are small, and numerous in both jaws, with a cluster of small ones on the vomer: when the mouth is extended the membranes are particularly transparent. The branchiostegous membrane is also remarkably clear; rays 3+4. The whole of the upper surface, including the eye-lids, cheeks and body, is rough, being covered with small scales, denticulated on their edges, which appear to be turned up: the head is rougher than the body. The upper eye is larger than the under one. The lateral line rises over the upper angle of the opercu-