AUSTRALIAN HALACOSTRACA. 301 



519. Zuzara emarginata. A.M. 



Zuzara emarginata, Haswell, 1. c, p. 7, pi. iii., fig. 5. 



Surface nearly smooth, very finely punctate. Head rather 

 prominent, narrowing gradually towards the front. Pirst segment 

 of the thorax not quite so long as the two following taken together ; 

 sixth segment as long as the first ; seventh segment very large, 

 nearly concealing the abdomen ; median posterior process very 

 long, extending far beyond the extremity of the abdomen, slightly 

 curved downwards, emarginate at apex a prominent, acute tooth 

 on either side of the segment near the base of the process. Last 

 segment of the abdomen with a rounded swelling on either side. 

 Terminal notch deep about one-sixth of the width of the 

 abdomen ; mesial lobe very prominent, extending beyond the 

 boundaries of the notch, truncate and faintly emarginate. Basal 

 joint of the internal antennae very large, notch for second joint 

 wide, with a prominent tooth on either side ; third joint slender, 

 not longer than the second, flagellum shorter than the peduncle. 

 Outer antenna} much longer than the inner, more than a third of 

 the length of the body, fourth and fifth segments of the peduncle 

 subequal, flagellum longer than the peduncle. Outer ramus of 

 uropoda subovate the outer border nearly straight, the inner 

 convex, the apex subacute ; inner ramus of about the same length 

 as the outer, bent directly backwards about the middle of its 

 length, apex subacute ; both rami fringed with hair. Colour 

 light red with darker spots on the thorax. Length ^ in. 



The females and young males have the seventh thoracic 

 segment small, the posterior process short or absent, the mesial 

 lobe less prominent, and the uropoda relatively smaller. 



Griffiths' Point, Western Port. 



This species is apparently a tolerably near ally of Ci/modocea 

 armata of Milne-Edwards, but in the latter species the posterior 

 prolongation of the seventh thoracic segment is described and 

 figured as conical, and the posterior lobe as bifid. 



Genus Calyptttra, Haswell. 



General form of the body as in Ci/modocea. Last segment of 

 the thorax produced behind into a broad plate, covering the 

 abdomen. 



