Amphipod Orclicstia tucinaima, Fritz Midler. 379 



0. tuciirauna ami is common on all New Zealand coasts, 

 also occurs on the coasts ot" (!liile, and, as I have pointed out 

 elsewhere, numerous other Crustacea have a simihir distri- 

 bution — tor exam[)h', tlie shore Isopod, I)eto bucrulenfa 

 (Xicolet), which is t'ouutl in New Zealand (inclu<lini^ the 

 outlyinj^ (.'hatham Islands) and in Chile, South America (see 

 Cliilton, l'J09 A, p. 602, 1909 b, p. 799, and 1915, p. 453). 



I ;;ivc below a specific diai^nosis, with f^^uresot' the species 

 0. tucurauna, and a few ailditional notes on its structure. 



I wish to express my grateful thanks to my assistant, 

 Miss E. M. llerriott, M.A., for the care she lias taken in 

 preparing the drawings for this paper. 



Orchestia tucurauna, Fritz Miiller. (Text-figs. 1-14.) 



O, tucurauna (also printed O. tucuratinya), Fritz Miiller, 18G4, ' Fiir 

 Darwin,' p. 54, li^js. ">0 & 51, and 1869, ' Facts and Arguments for 

 Darwin,' p. "'.>, tigs. 50 & 51. 



O. tucurauna, Stebbing, I'JOG, p. 534. 



O. auUnsoni, Stebbing, 1899, p. 400, pi. xxx. c, and 190G, p. 541. 



O. redniani, sp. n., Chilton, M.S. 



? O. dentata, Filhol, 1885, p. 462, pi. liii. fig. 1. 



Specific Diagnosis. 



Male. — Side-plates not deep, anterior lobe of side-plate of 

 perajop )d 3 much deeper than the posterior lobe. Pleon- 

 segmont 3 with postero -lateral angles quadrate, acute, scarcely 

 produced, posterior margin with a few short setse. Eyes of 

 motlerate size, round. Antenna 1 not reaching to end of 

 penultimate joint of antenna 2, first joint as broad as long, 

 second and third each a little longer than the preceding ; 

 tiagellum of four to six joints, the first three being coalesced, 

 subequal in length to the peduncle. Antenna 2 stout, last 

 joint of peduncle longer and slightly more slender than the 

 peimltimate; flagellum subequal in length to the peduncle 

 and of about twenty joints, the first four or five more or less 

 completely coalesced, especially in old males. Gnathopod 1 

 with side-plate small, somewhat triangular, slightly |)roduced 

 anteriorly, its inferior margin bearing a few small setae ; 

 basal joint narrow at base, widening distally, its anterior 

 surface grooved; ischium without apical j)roccss ; carpus 

 with prominent, narrowly rounded, distal pellucid process; 

 propoil oblong, widening to the palm, and bearing distally a 

 rouniled j)ellucid process, palm not distinctly defined and 

 overlapped by finger; all the joints beset with numerous 

 short »etJB. Gnathopod 2, basal joint narrow at the base, not 

 broadening greatly distally, anterior surface grooved ; carpus 



