much variation, so that the ditifercnces noted are of little import- 

 ance compared with all the numerous points of agreement. The 

 thick fur on the perteopods is a very conspicuous feature. 



Locality:— Two miles up Buffalo River, taken with small 

 shrimp net on a muddy bottom- 



Parasi'HAEro.ma, n. g. 



Fifth and sixth segments of the pereeon laterally projecting 

 beyond the rest. First diyision of the pleon with its first com- 

 ponent segment conspicuous, the second overlapping it, and also 

 the seventh segment of the perteon. but not the third of the pleon. 

 of which the second, third, and fourth segments are, as usual, 

 coalesced in the middle; telsonic segment with blunt dorsal pro- 

 cess near the middle and shallowly concave emargination of the 

 apex. Epistome elongate, its apex prominent beyond the rostral 

 point of the head and between the somewhat projecting bases o£ 

 the first antennae. Second antennse geniculate between the 

 fourth and fifth joints. The trunk-limbs not bideritate in appear- 

 ance, a slender spine lying close within the nail. Hind peraeo- 

 pods slender. Last pleopods without conspicuous transverse 

 pleating. 



The generic name alludes to the obvious affinity between this 

 and other Sphseromidse. 



This genus agrees with Dyiuunoic, Leach, in having a simple 

 excavation of the telsonic apex, but several distinctive marks are 

 presented in the above definition. Dynamenc itself still remains 

 obscure, the adult male form not having been determined. Bate 

 and Westwood in their discussion of it (British sessile-eyed 

 Crustacea, vol. 2. p. 418) say, '' In our figures of the second 

 maxilla in D. rubra and Moiifagiii, only one of the lobes was 

 observed on dissection." Their figures, however^ show that thev 

 are referring nottothesecond butthefirst maxillae. Both pairs 

 are normal, as they might easily have satisfied themselves^ in the 

 two form>.i mentioned. 



It is possible that Cunningham's Cymodocea darzoinii if better 

 known might ])c included in this genus, although that species 

 has the outer branch of the uropods scarcely half as long as the 

 inner^ while in the species here to be described the outer branch 

 is fully as long as the inner (see Trans. Linn. Soc. London, 

 vol. 27, p. 499, pi. 59, fig. I, 187 1, and Studer, Isopoda of the 

 Gazelle, p. 18, Berlin, iJ 



Pakasi'haeroma PRo^[rxl•:^■s, n- sp. 



Plate 13. 



The head is much broader than its length, bounded by a slight 

 ridge in front of the eves, in advance of these bein"- folded 



