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Show 1881.] REV. O. P. CAMBRIDGE ON A NEW SPIDER. 683 the genital aperture, by the development of which alone its maturity could have been determined. It seems to me that this Spider is of the same species as two Brazilian males in m y collection of 3Lygale versicolor, C. L. Koch, of which the male only has, as yet, been described. There can be little doubt, however, that Koch's Spider is not of the same species as the Mygale versicolor of Walckenaer, of which this latter author had described previously only the female; and it has thus become necessary to rename Koch's species. I have therefore, in the present paper, described and figured the Spider lately living in the Zoological Gardens under the specific name of stradlingi, after Dr. Stradling, by whom it was brought to England. Some specific characters, and figures of the palpi, taken from one of the male spiders above mentioned, are also added. Order ARANEIDEA. Fam. THERAPHOSID^E. Genus HOMCEOMMA, Ausserer. {Mygale, Walck. ad partem.) HOMCEOMMA STRADLINGI, sp. ii. (Plate LX.) Mygale versicolor, C. L. Koch (non Walck.). Homceomma versicolor, Auss. ? Length of the female 23 lines, to the end of the falces 27 lines; length of the cephalothorax 10\, breadth at the widest part 9 lines ; greatest expanse of the legs (diagonally from the extremity of each of the first pair to the extremity of the opposite leg of the fourth pair) 6 inches. Cephalothorax longer than broad, rising gradually but slightly from the posterior to the anterior part; normal indentations strong ; that at the thoracic junction deep and curved, the convexity of the curve directed backwards. Its colour is brown-black, covered with a short dense pubescence; and with a few long, erect, bristly foxy-grey hairs on the eye-eminence, which is of moderate height, convex, of a transverse-oval form, and placed close to the fore extremity of the caput. Eyes subequal, forming a transverse oblong figure, the length nearly about double its width. Their general position is similar to that of a great number of others of this family; and a better idea may be obtained of it from the figures (3, 4) than by any description. Among other slight differences in the relative size and position of the eyes of Spiders of this group, Herr Anton Ausserer lays stress upon that afforded by the greater or less height of those of the central pair in relation to the fore-laterals. This may be ascertained by looking at the Spider from in front and holding it level, and on a level with the eye ; then connecting the central pair by a transverse line touching their fore margins, and continuing this line on each side, observe whether it passes above or cuts the fore-lateral eyes. In the present Spider a line so drawn would as nearly as possible touch the posterior margins of the fore-lateral eyes. These last are slightly the largest of the eight. 44* |