Three lateral lines on the left side, the upper and lower separated from the middle by twenty or twenty-one longitudinal series of scales: a single line on the right side. Two nostrils: one between the posterior parts of the eyes, the other in front of the lower eye. Eyes separated by a concave space, the width of which is more than that of the orbit; the upper eye considerably in advance of the lower: lips not fringed. The length of the snout is contained twice and a third in that of the head, the angle of the mouth being behind the vertical from the posterior margin of the eye, and nearer to the gill-opening than to the end of the snout. The rostral hook terminates below the front margin of the eye. The height of the body is contained four times and two-thirds in the total length, the length of the head five times and a half. The height of the dorsal and anal fins is two-sevenths of that of the body. Uniform brownish-grey. (Günth., Fish., iv. p. 495.) ON AN APPARENTLY UNDESCRIBED SPIDER FROM COCHIN CHINA. BY DR. ALBERT GÜNTHER. _Cyphagogus Mouhotii._ UNDESCRIBED SPIDER. Cephalothorax subovate, covered with fine, short, dense hairs, with a transverse groove between cephalic and thoracic portion, and with a deep impression in the middle of the upper surface of the latter. Eyes eight, unequal in size, disposed thus ·.::.·; the four middle occupy a slight protuberance in front of the cephalothorax, whilst the lateral are the smallest, and situated on the side of its anterior part. Falces articulated vertically, rather compressed, with a non-denticulated claw of moderate size at their extremity; the claw is received in a sheath at the lower end of the falces, the edges of the sheath being provided with some horny spines of unequal size. Maxillæ flat; the outer margins of both together form a card-like figure; their lower extremity is hairy; sternal lip between the maxillæ, elongate elliptical. Sternum ovate, covered with rather coarse hairs. Palpi of moderate length: the terminal joint is rather longer than the two preceding together, and armed with a minute non-pectinated claw. Legs rather robust, tapering, very unequal in length, the two anterior being nearly equally long, but much longer than the two posterior: the fourth is longer than the third: each is armed with a pair of minute claws.