M ACRVRA. SCHM1TT. 349 



as regards abdomen, carapace, and in general, rostrum, 

 are so very much alike within reasonable variational 

 limits as to render detailed descriptions of their 

 appearance rather superfluous. 



The presence and absence of epipodites on the 

 thoracic legs of some species is both significant and 

 diagnostic, but the thelycum and petasma furnish, so 

 far as I am aware, the best clues to the species. The 

 relative lengths of the fifth pair of legs and the third 

 inaxillipeds as compared with the antennal scale are 

 often helpful, though of somewhat doubtful value 

 specifically. 



The fifth pair of legs in this species exceeds the 

 tip of the autennal scale by from one-third to one-half 

 the length of the propodal joint, while the third maxilli- 

 peds reach to a third or a fourth of the length of the 

 scale from its tip. A basal spine is present on the 

 first tw r o pairs of thoracic legs, and epipodites are present 

 only on the third pair. 



The thelycum is as figured by Bate, and except for 

 the inclusion of the male of curmrostris, it is strange 

 that his very distinctive figure should have been confused 

 with other species. The transverse posterior plate is 

 broadly U-shaped, and encloses a more or less circular 

 depressed area. Anteriorly the circumference of this 

 area is somewhat indented by the convex posterior 

 margin of the median anterior plate, which is medially 

 sulcate to the extent of rendering it a broad, very 

 shallow Y-shaped trough. 



The fifth abdominal somite is about three-fourths 

 the length of the sixth, which in turn is nine-tenths 

 the length of the telson. On either side the telson 

 has a small subterminal marginal spine, in advance of 

 which on either margin there are one or two scarcely 

 perceptible spiuules. The second abdominal tergum, as 

 seems common to all the members of the genus Trachy- 

 peneus, carries a median compressed tubercle. The third 

 to sixth terga are sharply cariuated. 



The single male found in the same bottle with a 

 female of this species from seven miles N.N.E. of Bowen, 

 Queensland, in sixteen fathoms (P.3528 part), I am 

 inclined to consider the male proper to the species. There 



