64 G- O. Sars. 



off the longitudinal ones. Lower edges behind these striæ 

 finely ciliated, the ciliation occurring somewhat within the 

 margin. Ocellus much smaller than the eye. Antennulæ 

 reaching to the tip of the rostrum. Lip-plate with 2 well- 

 marked serrations about in the middle. Caudal part rather 

 narrow and elongated, supra-anal projection well marked, 

 and defined below Dy a deep sinus, lower corner rounded 

 and not produced, dorsal edge below the anal orifice minutely 

 serrate, denticles of the lateral rows very distinct, numbering 

 about 14 on each side, caudal claws with a rather strong 

 denticle at the base. Colour whitish, pellucid. Length of 

 adult female 0.43 mm. 



Eemarks. — This is a very distinct and easily recog- 

 nizable form, being especially remarkable for the strongly 

 marked and peculiar sculpture of the shell: hence the spe- 

 cific name here proposed. 



Occurrence. — Some female specimens of this pretty 

 form were found in a small aquarium prepared with mud 

 from Ipiranga. The specimens moved rather rapidly in a 

 somewhat jerky manner. 



32. Alonella nitidula, n. sp. 



(PI. X, figs. 7, 7 a). 

 Specific Characters. — Female. Carapace, 

 seen laterally, rounded oval or somewhat elliptical in out- 

 line, height almost equal to the length, posterior extremity 

 abruptly contracted and narrowly truncated at the end, dorsal 

 margin evenly arched, and descending behind rather steeply 

 to the supero-posteal corner, ventral rather convex, with the 

 greatest curvature in the middle. Head with the dorsal mar- 

 gin evenly convex, rostral projection somewhat produced and 



