150 



2. Frontal border produced into a good-sized, anteriorly blunt, plate. Caudal stylets wanting. 



27. S. decor ata 

 2'. Frontal border slightly produced. Caudal stylets good-sized 28. S.rnodesta 



3. Front strongly produced; seen from below, it tapers considerably towards the distal end, 

 then expands into a tolerably broad disk, the margin of which — except posteriorly — 

 is provided with a single row of fine processes 4 



3 '. Front broad and somewhat emarginate in the middle, the margin with some rows of 

 fine processes 31. S. marginata 



4. Frontal disk nearly circular 29. S. dispar 



4'. Frontal disk broader than long, with rectangular lateral angles 30. S.insignis. 



27. Sphaeronella decorata n. sp. 



(PI. VIII, fig. 3a— 3o; pi. IX, fig. la— lb.) 



FEMALE. The largest specimen, represented in fig. 3 a, is 2-15 mm. in length and 

 2'47 mm. in breadth, and it has laid six ovisacs; another specimen, only 133 mni. long and 

 1-52 mm. broad, has laid eight ovisacs. Thus the body is broader than long. The small 

 head is distinctly defined from the trunk; it is comparatively well chitinised all over, except 

 in the part which surrounds the mouth-appendages and is limited by the low lateral borders, 

 and this part, forming a triangle, is prolonged anteriorly beyond the antennulae, continuing 

 a rather good distance along the dorsal side of the head, where this peculiar extension termi- 

 nates in an acute angle (fig. 3 d). So there is no real frontal border. Antennulae (fig. 3 e) short, 

 2-jointed, the two first joints being coalescent; setae short. Antennae tolerably short, 2-jointed, 

 the basal joint short, second joint longer and thicker, terminal seta short. Maxillulae well 

 developed, additional branch good-sized, with a distinct foot. Maxillae middle-sized, basal 

 joint smooth, but numerous chitinous taps appear on the inner side of the large membrane 

 between the first and the second joints. Maxillipeds powerful and comparatively pretty long; 

 the basal joint on its anterior side and on a small part of its inner side, bears four or five 

 groups of very small prickles (rudimentary hairs), arranged in transverse belts; further, at 

 a short distance from the distal margin, a transverse row of very fine hairs, besides similar 

 hairs on the distal margin itself; second and third joints coalescent, the distal spine long 

 and rather slender, with fine processes on its inner margin; last joint a little expanded 

 towards its rounded, flattened end, which terminates in numerous fine processes arranged in 

 a line. The sub-median skeleton slightly developed; a ventral transverse list between head 

 and trunk, and adjoining the anterior margin of this list, an odd, good-sized, considerably 

 vaulted eminence, which is rounded, a little broader than long, and provided at its median 

 anterior part with a rounded protruding plate. Lateral margin of the head naked. Trunk 

 naked. Genital area (fig. la) considerably smaller than the head (fig. 3a), nearly as long as 



