562 On a neio Genus of Isopoda from Algiers. 



thoracic segments. Ceplialon richly tuLerculated and par- 

 tially flanked by the lateral plates of the first segment of the 

 niesosome ; lateral lobes well developed and turned upwards, 

 median lobes absent. Eyes large, subdorsal. Antennulte 

 (fig. 2) small, 3-jointed. Antennge (fig. 3) long, fifth joint 

 largest, the flagelluin articulating with the peduncle in deep 

 cavity, exceedingly mobile ; flagelliim 2-jointed, with a 

 smaller 2-jointed terminal portion. Mandibles (figs. 4 & 5) 

 stout, with four teetli and two tufts of setse. First maxillse 

 (fig. &), outer lobe with three large and four smaller in- 

 curved spines, inner lobe (fig. 7) with two setaceous spines- 

 on the inner border. Second maxillge thin and plate-like. 

 The segments of the niesosome 1-3 richly tuberculatod 

 with large processes, remaining segments with finer and 

 n)ucii smaller tubercles; lateral plates not expanded, pos- 

 terior angle overlapping next segment. Maxillipedes 

 (fig. 8) large and well developed ; the outer lobe termi- 

 nates in three small spines and a large multispinous 

 process ; inner lobe distally flattened with three small 

 niarginal spines. The ventral surface of the body is raised 

 and fringed outwardly with small sjnnes. Thoracic ap- 

 pendages (fig. 9) large and characterized by a Si;ries of 

 short blunt marginal spines, general surface of the segments 

 covered witli small pointed spines. On the second appendage, 

 at the distal end and outer side of the protopodite is a small 

 pit-like depression lined with minute spines (fig. 9, p.d.). 

 Abdominal appendages (figs. 10a— b), first small (probably 

 degeneiate), second (fig. 10 6), exopodite triangular in shape, 

 with knob-like thickening on the outer lower border, endo- 

 podite small. Uropoda (fig. 11) well developed, basal plate 

 large, exopodite broad and blunt, endopodite attached above 

 and on the inner border, slender, and shorter than exopodite. 

 Telson small and triangular. 



Length 22 mm. 



Colour (in alcohol) creamy brown, with slaty-grey abdomen. 



Hah. Algeria, 1873 (/. IF. Clark). 



Type. In the University Museum of Zoology, Cambridge. 



In the form of the anteniia3, first maxillas, telson, and 

 uropoda the genus shows a relationship with the genus 

 JS^iainbia, Budde-LuncI, but differs from the known members 

 of that genus in all other features. The peculiar form of the 

 lateral lobes of the head at once separate this genus from 

 any other I know of. Instead of being flat-like extensions 

 of the head disposed horizontally, they are turned vertically 

 inwards. There is no trace of any median lobe, the fiont of 

 the head gradually sloping over on to the epistoma. 



