A. D. MICHAEL ON TWO SPECIES OK ACAHINA. 119 



another between the second and third pairs of legs, two pairs on the 

 back standing nearly upright, and two pairs near the posterior 

 margin, all long ; and one other pair on the margin shorter, and 

 lower in level. There are conspicuous hairs on almost every joint of 

 each leg, those on the tarsi being the longest and most numerous ; 

 those near the insertion of the legs are sparsely pectinated. The 

 ventral surface has a pair of hairs. 



Description of the Female. 



The principal differences are that it is slightly smaller in size than 

 the male and the cephalothorax much shorter, the abdomen wider 

 and not square, but gradually diminishing, and with a rounded 

 posterior margin. The first pair of legs are thin and small, entirely 

 without the great club and claw of the male ; the second pair, on 

 the contrary, are thicker and stronger than in the male, but other- 

 wise similar ; the two hind pairs of legs are practically similar to 

 those of the male. The hairs are all longer and stronger than in 

 the male, and much more numerous round the hind margin and on 

 the ventral surface ; otherwise similar in position. The vulva ap- 

 pears to be in the central line of the ventral surface, but just behind 

 the fourth pair of legs, the labiae a little separated posteriorly, and 

 with a fine undulated sternite in front of it. The second lateral 

 ridge of the sternal skeleton is far less conspicuous than in the male, 

 and is more curved, and bends backward in two loops until it joins 

 the third ridge. The fourth ridge is straight, and goes entirely 

 across the body. The fifth ridge, on the contrary, is almost absent, 

 unless the sternite mentioned above be its homologue ; the fourth 

 epimera send bands above and almost round the hind legs. 



The rostrum of the female is longer than in the male. 



DESCRIPTION OF PLATES VI, VII. 

 Labidostomma luteum. Plate VI. 



Fig. 1. — Ntmph. — (a) The mandible, (b) Ultimate movable joint of ditto, 

 (c) Palpus, {d) Cephalothorax, (e) Chitonous plate on abdomen, (/) 

 Depressed channel, (ff) Raised reflexed margin, (It) Lateral projec- 

 tion stated by Kramer to be, or to be furnished with, an eye, (i). 

 Stigma. 



Fig. 2. — Perfect Creature. — The above explanations (except eto g) would 

 be applicable to this figure also. 



