300 AUSTRALIAN MALACOSTEACA. 



produced backwards. Last segment of the thorax produced in 

 the middle line behind into a rather slender process, which is 

 about equal in length to the three preceding segments, sub- 

 cylindrical, but depressed dorso-ventrally, not dilated at the apex, 

 which is truncate. First segment of the abdomen short, with 

 well-marked divisional lines. Last segment convex, marked in 

 the middle line near the proximal border with a faint key-hole- 

 shaped depression, surrounded by a very obscure, granular 

 elevation ; terminal notch with a prominent narrow, clavate, 

 mesial process. Inner antennae separated at the base by a very 

 small frontal process ; basal segment of peduncle broad ; second 

 shorter and narrower ; third slender, cylindrical, longer than the 

 second, but not quite so long as the first and second together ; 

 flagellum rather longer than the peduncle. Outer antennae with 

 the peduncle stout, last joint the longest; flagellum nearly twice 

 as long as the peduncle. Rami of the uropoda thin and leaf- 

 like, immobile ramus falciform with a truncate apex ; mobile 

 ramus ovate-lanceolate in outline, concave upwards, with a raised 

 margin, much longer than the inner, and extending far beyond 

 the extremity of the abdomen. 



Female. Differs from the male mainly (1) in wanting the 

 posterior prolongation of the last thoracic segment, (2) in the 

 absence of the terminal notch, (3) in the smaller size of the 

 uropoda, the rami of which are nearly equal, the mobile ramus 

 being capable of being entirely concealed under the inner. 



A common species in Port Philip ; also found in Tasmania. 



I have placed this and the following species in the same genus 

 with Zuzara diadema and Z. semi-punctata of Leach,* all three 

 being characterised by the prolongation backwards of the last 

 segment of the thorax in the male, and by the possession of a 

 posterior mesial notch occupied by a slight median process. Both 

 Z. integra and Z. emarginata have the outer ramus of the uropoda 

 capable of folding underneath the inner. The present species 

 differs from Z. semi-punctata in the process of the last thoracic 

 segment not being graimlous at the base or punctated above, and 

 in having the outer ramus of the uropoda truncate instead of 

 pointed. From Z. diadema it differs in not having the process of 

 the last thoracic segment terminally dilated. 



* DicLionuaire des Suieuccs Naturelles, tome xii., p. 344. 



