244 COLLECTIONS FROM MELANESIA. 



naked except toward the margins, the lower margin is in a straight 

 line with the lower margin of the immobile finger ; the fingers are 

 little shorter than the palm, acute at apices, and rather strongly den- 

 ticulated along their inner margins. The ambulatory legs are slender 

 and somewhat elongated, the dactyli styliform and straight, the 

 margins (of the fifth pair especially) are clothed with longish 

 hairs. The male verges are slender ; their bases lie in narrow 

 canaliculi, which are partially open above. Colour (in spirit) light 

 yellowish. Length nearly 3 lines (6 millim.), breadth about 3 lines 

 (6| millim.). 



The single male in the collection was obtained at Port Darwin, at 

 a depth of 12 fms. 



This species is distinguished from Typldocarchius nudus and 

 T. villosus, Stimpson, by the form of the merus-joint of the outer 

 maxillipedcs and the acnte anterior margins of the ocular peduncles, 

 in which characters it agrees with Geratoplax ; in the form of the 

 carapace and the structure of the antenna? it agrees better with 

 Typhlocarcinvs ; but the very name of the latter genus prevents my 

 assigning to it a species which has the organs of vision normally 

 developed. Both this and the following species must, I think, be 

 regarded as intermediate forms between Typhlocarcinus and Cerato- 

 plax. The fifth ambulatory legs are much shorter than the pre- 

 ceding, as in Asthenognathus incequipes, Stm. : but, unlike that 

 species, the ambulatory legs are all very slender. 



Rhizopa gracilipes, Stimpson, to which this species is nearly allied, 

 is described as having minute eyes, a straight frontal margin, a 

 strong median frontal suture, and glabrous chelae. 



88. Ceratoplax ? laevis. (Plate XXV. fig. C.) 



In this species the carapace is transverse, smooth and shining, lon- 

 gitudinally moderately convex, with only a very few punctulations ; 

 the front somewhat deflexed, more than one third the width of the 

 carapace, entire, with an indistinct transverse line of scanty hairs 

 across its upper surface ; the antero-lateral margins are much shorter 

 than the postero-lateral, acute, entire, and bordered with a few hairs ; 

 the postero-lateral margins are straight and convergent to the pos- 

 terior margin. The orbital margins are entire, the orbits widest 

 internally. The epistoma is very narrow-transverse. There are no 

 longitudinal ridges on the endostome or palate. The pofetabdominal 

 segments (in what appears to be the young female) are all of them 

 distinct and all narrow except the last, which reaches to the bases 

 of the fifth ambulatory legs. The eye-peduncles are thick and hairy 

 above the cornea?, distinct, and black ; the basal antennal joint, 

 which is of moderate size, reaches to the subfrontal lobe (see fig. o). 

 The ischium-joint of the outer maxillipedcs is little longer than 

 broad ; the merus is transverse, with its antero-external angle pro- 

 minent and rounded : there is no notch at the antero-internal angle. 

 The chelipedes are subequal and of moderate size ; the merus short 

 and trigonous, with a strong tooth near the distal end of its upper 



