330 RECORDS OF THE AUSTRALIAN MUSEUM. 



orbit and the postorbital spine N. tumida is intermediate 

 between Naxia and Microhalimus, and as regards the legs, the 

 penultimate joint is often as little dilated in N. aurita 

 Latreille 11 as in M. deflexifrons. 



Naxia, Microhalimvs, and an allied new genus Zewa, may be 

 distinguished as follows : — 



a. Eye-stalks of medium length, not or barely reaching the 

 anterior hepatic spine when laid back. Penultimate 

 joints of ambulatory legs more or less dilated. 



b A post-ocular spine separated from the orbit by a 

 more or less distinct interspace ; postero-superior 

 orbital spine present or absent. Penultimate 

 joints of legs usually much compressed and dilated 

 distal ly Naxia. 



bb. No post-ocular spine, only a postero-superior 

 orbital spine. Penultimate joints of legs very 

 little dilated Microhalimus. 



aa. Eye stalks long and slender, reaching to or beyond the 

 anterior hepatic spine when laid back. Penultimate 

 joints of legs cylindrical, not dilated Zewa. 



Naxia (Microhalimus) deflexifrons, Hasicell. 



(Plate x, tigs. 1—4). 



Microhalimus deflexifrons, Haswell, Proc. Linn. Soc. N. S. 

 Wales, iv., 1880, p. 435, pi. xxv., fig. 2, and Cat. Austr. 

 Crust., 1882, p. 7. Id., Wl.itelegge, Proc. Roy. Soc. N. S. 

 Wales, xxiii., 1889, p. 225. Id., Fulton and Grant, Proc. 

 Roy. Soc. Vict., xix, (n.s.), 1906, p. 16. 



Carapace subpyriform, the regions well defined and the 

 surface uneven but smooth ; together with the legs, it is more or 

 less densely covered with hooked hairs, among which are groups 

 of stronger, curled ones. Branchial regions with two short but 

 strong lateral spines followed by a tubercle ; a second smaller 

 tubercle may be present anteriorly, above the first spine. A 

 rounded tubercle on the hinder margin of the carapace on the 

 median line, and another just in front of it. A low swelling is 

 present on either side near the groove between the branchial and 

 gastric regions, and the cardiac region may tend to form two 



11 Latreille — see ante. 



