GENUS OF TEEEESTRIAL ISOPODA. 445 



In its small size, more slender antennce, and in the slender spiny 

 perseopoda and the uropoda, this species at first shows a general resem- 

 blance to a Triclioniscus ; the mouth-parts are, however, as was first pointed 

 out by Stebbing (1900, p. 565), quite different, and the species is a 

 true Deto. 



The mouth-parts are similar to those of D. acinosa, and do not require 

 special notice ; the maxillipeds have been figured by Budde-Lund (1906, 

 pi. 4, fig. 40) from a specimen given by me to the Zoological Museum of 

 Dundee University College. 



The legs (figs. 21 & 22) are slender, and in the arrangement of the spines, 

 particularly of the large split spine towards the distal end of the carpus, are 

 very similar to those of Triclioniscus and. allied genera ; the dactylar seta is 

 fairly prominent — it has only two branches, one of which bears a small knob 

 at the end. 



The adult male is not known ; it will be interesting to see in what 

 characters it differs from the female. 



Deto aucklandi^ {G. M. Thomson). (PL 39. figs. 24-30, and 

 PL 40. figs. 31-44.) 



Actcecia aucMandice, G. M. Thomson, 1879, p. 249. 

 „ „ Budde-Lund, 1885, p. 239. 



„ „ Filhol, 1885, p. 443. 



Scyphax (?) micklandice, Chilton, 1901, p. 126, pi. 15, fig. 2, 

 Deto aucklandice, Chilton, 1906, p. 273. 



„ „ Budde-Lund, 1906, p. 87. 



„ „ Chilton, 1909, p. 666. 



„ „ Chilton, 1910, p. 288. 



Deto magnifica, Budde-Lund, 1906, p. 86. 

 Deto robusta, Budde-Lund, 1906, p. 86. 



Specific description. — Male. Oblong-oval, moderately convex, head strongly 

 tuberculated, with a raised oblique ridge running from near the centre 

 outwards and backwards to the posterior margin; in the centre between 

 these ridges are four tubercles, the posterior two larger than the two 

 anterior, other small tubercles near the frontal margin ; lateral lobes large, 

 directed outwards, roundly tetragonal. 



First segment of perseon slightly longer than the others, Avhich are suh- 

 equal, each segment bearing a transverse row of tubercles or rounded 

 blunt-ended spines, which are directed upwards and a little backwards, the 

 lateral ones the largest and longest, the others gradually diminishing in size 

 towards the median line ; in most cases there are ten tubercles in each row, 

 but there are usually fewer on the first and last segments of the perseon ; 

 in the first two segments there are usually some slight tubercles in front 

 of the transverse row. Pleon with first two segments short and without 

 epimeral expansions, third, fourth, and fifth with large epimeral expansions 



