42 ON THE AUSTRALIAN SPECIES OF PENiETJS, 



the following points ; — ( 1 ) the rostrum is a shade higher and 

 more compressed ; (2) the peduncles of the antennae are rather 

 shorter ; (3) the anterior pair of legs are bispinous ; (4) there 

 is no marked dorsal carina on the carapace. 



Length of female 3^ inches ; of male 2^- inches. 



Hah. Darnley Island ; Cape Grenville ; Cape York (Chevert 

 Exped.). 



7. Penseus Mastersii, sp. no v. 



Rostrum reaching nearly as far as the end of the antennary 

 scale, slender, nearly straight ; armed above with eight or nine 

 teeth, of which the last is separated by a wide interval from the 

 penultimate ; unarmed below ; continued back into a non-sulcate 

 carina which does not reach to the posterior margin. A slight 

 lateral groove at the side of the rostrum, not continued backwards. 

 Carapace smooth ; supra-orbital spine rudimentary ; hepatic and 

 antennary spines present, acute ; grastro-hepatic sulcus deep ; 

 cervical suture well-marked in its anterior half. Eyes large ; 

 flagella of antennules equal in length to the two last segments of 

 the peduncle. External maxillipedes rather slender ; palp 

 extending to the distal end of the antepenultimate joint of the 

 endopodite. First three pairs of legs, as usual, progressively 

 increasing in length from before backwards ; fourth much shorter 

 than third ; fifth of about the same length as the latter ; first 

 three pairs with a spine on the under surface of their second joint. 

 Fourth, fifth, and sixth segments of abdomen carinated, the 

 carina on the sixth segment ending in a small spine ; the posterior 

 border of the first, second, fourth, and fifth with a notch on each 

 side — shallow and wide on the first and second, deeper and 

 narrower on the fourth and fifth. Last abdominal segment 

 mesially grooved, and with a slight lateral groove near each 

 external border, apex pointed but not markedly spiniform; lateral 

 margin devoid of spines. 



Length 3f inches. 



Hah. Port Darwin (Chevert Exped.). 



