440 I'ROF. C. CHILTOK ON DETO, A SUBANTARCTIC 



the fully clevelo[)ed male ; unfortunutelj the male in D. marina is not known. 

 The others may, however, be distinguished as follows : — 



A. Uropod with exopod reaching mucli beyond the 



endopod Subgenus Deto, Budde-Liind. 



1. Male with a pair of long spines on each segment of 



perseon, pleon witnout spines D. echinata. 



2. Male with a pair of spines (or prominent tubercles) on 



eacb segment of perseon, and on third and fourth 



segments of pleon D. armata. 



3. Male with a pair of tubercles (not spines) on each seg- 



ment of person D. acinosa. 



4. Male unknown ; female with surface granular, or with 



low tubercles only D. marina. 



B. Uropod with exopod not reaching beyond endopod. Subgenus T7«?ze^«, Budde-Luiid. 



1. Male with lateral portions of first segment of perteon 



not expanded ; surface of perseon with prominent blunt 



spines J), aucklandice. 



2. Male with lateral portions of first segment of perajon 



forming balloon-like expansions ; surface of pera?on 



with irregular pointed tubercles D. buccidentu. 



Deto echinata, Guf'nu. (PL 39. figs. 1-3.) 



Deto echinata, Guerin, 1836, notice 21, p. 2, pi. 14. 



„ „ Milne-Edwards, 1840, vol. iii. p. 174. 



,, ,, Krauss, 1843, p. 63. 



,, „ Heller, 1868, p. 1.37. 



,, ,, Budde-T.uud, 1879, p. 9. 



„ „ Budde-Lund, 1885, p. 234. 



„ „ Stebbing, 1893, p. 431, 



„ „ Budde-Luod, 1906, p. 85. 



„ „ Stebbing, 1910, p. 444. 



? Deto Whitei, Kiuahan, Dublin Zool. Bot. Assoc, i. p. 199, pi. 19, fig. 6; see also 

 Ann, & Mag. Nat Hist. ser. 5, vol. xvii. p. 83. 



Male. — Oblong-oval, more than twice as long as broad. Head with a 

 prominent subacute tubercle on each side near the posterior margin and 

 internal to the eyes, with another smaller tubercle anterior and interior to 

 the first ; rest o£ surface granular ; lateral lobes moderately large, directed 

 outwards and forwards, their extremities broadly rounded. 



Each segment of pera3on with a pair of long acute spines, straight or 

 slightly curved, arising near the posterior margin and projecting vertically, 

 those on the posterior segments directed also a little backwards ; the spines 

 on the first segment are the shortest, those on the succeedino; seo-ments 

 longer till the fourth and fifth, which are subequal and much longer than 

 the segment from which they arise, each of the sixth and seventh a little 

 shorter than the preceding one. Rest of surface of pergeon finely granular 



