AUSTRALIAN MALACOSTEACA. 291 



the thorax produced, curved backwards, sub-acute. Penultimate 

 segment of the abdomen produced behind into a rounded tubercle I 

 a pair of sub-conical elevations on the last segment of the 

 abdomen ; notch very shallow, quadrangular ; lobe pointed. 

 Rami of caudal appendages rather unequal, both extending 

 beyond the extremity of the segment, the outer the longer, the 

 apes acute, curved outwards, the outer border with a conical 

 tooth ; the inner sub-acute. Basal joint of superior antennae 

 very broad, notched distally for the reception of the second joint. 

 Flagellum of inner antenna? with twenty-seven articuli ; that of 

 the outer pair with twenty-one. Length of longest specimen 

 1 in. 



Port Jackson ; Port Stephens. 



502. Cymodocea aculeata. A.M. 

 Cymodocea aculeata, Haswell, 1. c, p. 471, pi. xvi., fig. G. 

 Body strongly convex, finely granular. First segment of the 



thorax twice as broad as the rest. Last segment of the abdomen 

 with two prominent tubercles situated near the middle line, and 

 two smaller ones external to them. Terminal notch very deep, 

 quadrangular, the lateral processes triangular, central process 

 very prominent, projecting slightly beyond the extremity of the 

 lateral. Inner antennae with the basal joints very broad and 

 compressed, flagellum with twenty-two or twenty-five articuli. 

 Outer antennae rather longer than the superior pair ; flagellum 

 with about fourteen to sixteen articuli. Rami of caudal appen- 

 dages sub-equal, outer ramus sub-ovate, with the outer border 

 straight, the inner convex ; inner ramus oblong, emarginate. 

 Length A in. 

 Port Jackson. 



503. Cymodocea bidentata. A.M. 



Cymodocea bidentata, Haswell, 1. c, Vol. vi., p. 8. 



Body clothed with slender hairs which are scanty on the 

 anterior thoracic segments, but longer (some about one-sixteenth 

 of an inch) and more abundant on the abdomen and uropoda. 

 Head strongly convex, smooth. Pirst segment of the thorax 

 longer than the two following together, ornamented with faint 

 longitudinal lines of minute granules ; lateral border strongly 



