294 



Transactions'. 



widely distributed in South Africa. In 1910 (p. 222) Barnard adopts 

 the genus, transfers to it the Australian species Talitrus sylvaticus Haswell 

 and T. kershawi Sayce, and gives a fresh diagnosis. 



It seems probable that Talitriator will be found to be identical with 

 Talitroides Bonnier, and this name has priority if the genus is retained 

 as separate from Talitrus. 



All the New Zealand species of Talorchestia, and, so far as I know, all 

 the foreign species also, are confined to sandy beaches, where they may 

 be found under decaying seaweed or driftwood, or burrowing into the sand 

 about high-water mark. Some species of Orchestia may occur in similar 

 situations, but many are found under stones, &c, on rocky shores. 



Owing to the differences between the sexes and to the changes passed 

 through by the males in attaining the adult form it is very difficult to give 

 any artificial key for readily distinguishing the species, but perhaps the 

 following will be useful : : — 



1 Antenna 2 as long or longer than the head and first three segments 

 of the peraecn, fourth and fifth pereeopoda not modified in male . . T. quoyana. 

 Antenna 2 shorter than the head and first three segments of peraeon, 

 fourth or fifth peraeopod modified in male . . . . . . '2 



(Body very broad; carpus of fourth peraeopod irregularly dilated in 



"male, fifth peraeopod normal .. .. .. .. T. tumida. 



Body rather compressed ; carpus of fifth peraeopod dilated in male 

 into a large, rounded plate concave on inner side, fourth peraeopod 

 normal . . . . . . . . . . . . . . T. telluris. 



Talorchestia quoyana (Milne-Edwards). (Figs. 1 to 5.) 



Talitrus brevicornis and Orchestia quoyana H . Milne-Edwards, 1840, 

 vol. 3, pp. 15, 19. Orchestia quoyana G. M. Thomson, 1899, 

 p. 202. Talorchestia quoyana Stebbing. 1906, p. 547 (with 

 synonymy). 



Specific Diagnosis. — Back broad. Antenna 1 reaching a little beyond 

 end of penultimate joint of peduncle of antenna 2. Antenna 2 in female 

 as long as head and first three segments of peraeon. in male becoming longer 



Fig. 1. — Talorchestia quoyana, male. 



and stouter, often more than half the body-length and with last joint of 

 peduncle twice as long as the preceding. Gnathopod 1 in male with carpus 

 much longer than propod, not lobed, propod very spinose, with small postero- 

 distal lobe, palm transverse, finger reaching beyond it. Gnathopod 1 in 



