291 AUSTRALIAN MALACOSTEACA. 



two teeth separated by a deep, broad and semi- circular excavation. 

 Kami of the caudal appendages foliaceous and each ending in a 

 point, the external a little longer than the internal. Length 

 about 4 lines. [M.-E.~\ 



Australia (Mus. Paris). 



508. Cerceis acuticaudata. A.M. 



Sphaeroma ? acuticaudata, Haswell, 1. c, Vol. vi., p. 11., pi. iii., 

 fig. 9. 



Greatest breadth of body about two-thirds of the total length. 

 Head broader than long, bordered anteriorly and laterally by a 

 thickened margin which is continuous with the eye ; an obscure, 

 mesial, longitudinal carina on the anterior half, and a mumber of 

 smooth, flattened tubercles. Surface of the thoracic segments 

 smooth, each bordered with short hairs ; first segment not so long 

 as the two following taken together ; lateral borders of thoracic 

 segments carinate ; the postero-lateral angles acute. Last segment 

 of the abdomen slightly dilated an acute spine about its centre, 

 below which is a transverse band of short hairs ; a deep, rounded, 

 median posterior notch, with prominent acute angles. Basal 

 joint of internal antennae much compressed, not much longer than 

 broad, separated from its fellow by a small rounded frontal lobe ; 

 second joint sub-triangular, more than half the length of the first ; 

 third about half the length of the second and slender; flagellum 

 rather shorter than the peduncle. Outer antenna? more than 

 half the length of the body ; terminal joint of the peduncle longer 

 than the rest. Outer ramus of uropoda longer than the inner, 

 projecting far beyond the extremity of the abdomen, lanceolate- 

 acute, with an acute tooth on its inner border. Inner ramus 

 extending slightly beyond the extremity of the abdomen, 

 acuminate. Length f in. 



Griffiths' Point; Port Philip. 



This species is certainly a Cerceis, and is evidently a close ally 

 of C. bidentata, from which it differs in having a mesial spine in 

 place of two small bosses on the upper surface of the last 

 segment of the abdomen. Sphceroma oricntaJia of Dana is like- 

 wise nearly related. 



