276 COLLECTIONS FROM MELANESIA. 



he does not notice that the outer margin of the smaller chelipede 

 is armed with a series of minute spinules, which are often concealed 

 hy the pubescence. The smaller chelipede in the adult male and 

 both chelipedes in the sijialler specimens have the anterior margin 

 of the wrist armed with two teeth, and in the smaller specimens 

 (which yet I cannot think belong to a distinct species) the frontal 

 and upper orbital margins are very minutely spinulose. There is 

 developed in both chelipedes a more or less distinct longitudinal 

 median ridge on the upper surface of the wrist and palm, and the 

 outer margin of the hand in both is armed with a series of small 

 spinules, so that these specimens in many points resemble Porcellana 

 omata, Stimpson, from Hong Eong. 



20. Porcellana quadrilobata. (Plate XXX. fig. D.) 



In the single male from Port Denison, 4 fms., thus designated, the 

 carapace is shaped nearly as in Porcellanella triloba, that is, it is much 

 longer than broad, with the sides very slightly arcuated. The upper 

 surface, when viewed under a lens of suflScient power, is seen to be 

 marked with numerous rather closely-set transverse striae. Theinter- 

 antennulary portion of the front, which in P. triloba is entire, is in P. 

 quadrilobata divided by a median triangular notch (which, however, 

 is not so deep as the lateral notches), hence the front appears 4-lobed. 

 The lobes are triangular and acute ; on the inner margin of each of 

 the outer lobes is a small spinule, and the inner margins of each of 

 the inner lobes is minutely serrated. There is a very small tooth or 

 spine at the outer orbital angle, and posterior to this the sides of the 

 carapace are armed with five spines, the three posterior of which are 

 placed near to one another and separated by a somewhat wider in- 

 terval from the preceding tooth. On the inferior surface of the cara- 

 pace, below the inferior orbital margin, there is a strong spine. The 

 eyes are set on very short pedicels, and are nearly concealed within 

 the orbits. The joints of the peduncles of the antennae are short (the 

 flagella wanting in the single specimen examined). There is a spine 

 at the distal end of the basus-joint of the outer maxillipedes ; the 

 ischium-joint is somewhat dilated, scarcely at all emarginate at its 

 distal end, where it is articulated with the merus, which is excavated 

 at its distal extremity ; the three following joints are moderately 

 robust. The chelipedes are proportionately rather slender and elon- 

 gated ; the merus or arm is short, its inner margin somewhat cristi- 

 form, and terminating in a thin subacute lobe ; there is a spine also 

 on the under surface of the merus ; the wrist is about as long as the 

 palm, and is armed with three spines or teeth on its inner margin ; 

 the hand is slightly contorted ; the surface both of hand and wrist 

 finely- striated ; the fingers are rather shorter than the palm, meet 

 along their inner edges when closed and cross at the tips, which are 

 incurved ; at the bases of the inner margins of the fingers is a patch 

 of hair ; the lower margin of the lower finger is arme^^with a series 

 of small spinules. The ambulatory legs are rather slider ; there are 

 a few short stiff setce, or mobile spines, at the distal end of the 



