399 



portion in S. minuta are also quite absent. The terminal 

 segment, however, is distinctly keeled and has the lateral mar- 

 gins slightly curving inwards. The lateral margins of the 

 epimera are smooth and without serrations, but in some cases 

 they bear a few small hairs. 



The antennae are similar to those of S. minuta. The 

 first pair of legs (fig. 12) are similar to those of S. minuta, 

 the setae on the palm of the first pair are of smilar shape ; 

 the second pair in the male (fig. 13) has the palm provided 

 with two rows of 4 or 5 stout setae each, the dactyl has a 

 terminal portion separate from the broader basal portion, but 

 shorter than the corresponding part in S. minuta. The 

 remaining legs bear long slender setae, but apparently no ser- 

 rated .spines. In the uropoda (fig. 14) both branches are 

 narrow and have the posterior margins dentate, the dentations 

 being most distinct on the outer branch, which is very slightly 

 shorter than the inner. 



Specific Diagnosis. 



Body almost circular, caudal shield projecting only a 

 little beyond the outline of the circle. Rostrum very short. 

 Posterior margin of head provided with three blunt tubercles. 

 Terminal segment with extremity narrow and rounded, its 

 dorsal surface with conspicuous keel. Dorsal surface of body 

 smooth and without median and lateral tubercles. Epimera 

 of sixth segment of peraeon extending to the first third of 

 the caudal shield, those of the third pleon segment reaching 

 to the middle of the shield. Uropoda with both branches 

 narrow, outer with external margin obscurely serrate, end 

 dentate or crenate, and with one or two hairs, inner branch 

 a little longer and with end less distinctly serrate. 



In other respects resembling S. minuta. 



Length, 6 mm. ; breadth, 5 mm. 



Locality. — Encounter Bay, South Australian coast. 



I have pleasure in naming this species after Mr. W. H. 

 Baker, F.L.S., Hon. Curator in Crustacea at the South Aus- 

 tralian Museum, who has done so much good work on the 

 Crustacea of South Australia. 



(*>) On Deto marina, Chilton. 

 Figs. 15-21. 



About two years ago I published a paper (1915) on the 

 terrestrial Isopoda belonging to the genus Deto in which I 

 recognized the following species : — D. echinata, Guerin, and 

 D. acinosa, Budde-Lund, from Cape Colony; D. armata, 

 Budde-Lund, from St. Paul Island, Indian Ocean; D. marina, 



