644 Mr. R. Gurney on some 



Spiracular channels broad, opening directly on to or close 

 to tlie margin, closely studded with tubular ducts. Dorsum 

 with irregularly disposed series of small, densely chitinous, 

 cribriform plates (fig. 3, c) varying in size, form, and number 

 of pores, but always much smaller and less conspicuous than 

 those oi formicaram, each plate with a narrow, sharply defined, 

 paler outer border. Derm of dorsum a ith smaller and larger 

 pores (the latter thick-rimme 1) and with transverse series of 

 spiniform seta3, which are larger and more numerous on the 

 abdominal segments. Anal operculum surrounded by a 

 densely chitinous zone, sprinkled with small pores and larger 

 ovoid lacuna3. Anal ring with sixteen (or more) stout set^e. 

 Margin of body without fringe of spines or setse. Stigmatic 

 clefts obscure, without stigmatic spines. 



Length of average examples 2*5 mm. 



Nymph very similar to the adult, but smaller and flatter, 

 and without a denser chitinous area surrounding the anal 

 aperture. Antenna 5-jointed, the basal joint in the form of 

 a narrow band, second joint largest. Legs (fig. 3, e) reduced 

 to conical points, with obscure traces of partial segmentation ; 

 with a minute apical claw. Cribriform plates as in adult, but 

 often less strongly chitinized. Anal ring with ten setse. 

 Spiracular channels opening directly on to the margin. No 

 stigmatic spines. No marginal spines or setse. 



Larva not observed. 



Coimbatore, India. 



On roots of Cassia sp. Coll. T. V. Raraakrishna (no. 204), 

 9. iii. 1921. 



LXX. — Some new or rare British Crustacea. 

 By Robert Gurnet, M.A. 



1. Canthocamptus echinatus, Mrazek. 



In July 1919 a few specimens of a species of Canthocamptus 

 resembling C. echinatus were taken at Flordon Common near 

 Norwich, but I was unable at the time, with the scanty 

 material available, to determine its identity with certainty, 

 and I was unable to find the species again on a second visit 

 to the spot. In 1920 the same form was found in considerable 



