On the Shell o/Neiitiiia fluviatiliH. ;JG9 



Parasphecodes brijulrichus sordidulus, subsp. u. 



? . — Smaller, length about 7^ mm. 



Abdomen dusky, the hind margins of the segments espe- 

 cially with dusky suffusion ; first r. n. entering apical corner 

 of second s.m. 



Hab. Brisbane, Queensland, Aug. 5, 1913 [Hacker ; 

 Queensl. Museum, 122). 



Halictus oxoniellus, sp. n. 



? . — Length about 5 mm. 



Of ordinary form, with thin white hair ; head and thorax 

 black, except the nifsothorax and scutellum, which are a 

 fine dark blue ; mandibles and antennae black ; teguke 

 ferruginous, clouded with piceous. Wings dusky hyaline, 

 the stigma large, piceous, obtuse apically ; nervures dilute 

 sepia, outer r. n. and t.-c. almost wholly obsolete, first r. n. 

 entering second s.m. Legs black, the small joints of middle 

 tarsi reddish ; hind femora thin and arched, hind tibife very 

 robust ; hind spur with three large teeth. Abdomen bright 

 ferruginous, the first segment black except a broad apical 

 band, the other segments with black patches on extreme 

 lateral margins ; A'cnter with long curled hairs, mesothorax 

 shining in front, dull behind ; area of metathorax with very 

 delicate raised lines, evanescent apically ; clypeus slightly 

 metallic, with a microscopically tessellate sculpture and 

 sparse punctures ; front minutely striate. 



Hab. Bribie Island, Queensland, Nov. 2, 1913 [Hacker ; 

 Queensl. Museum, 108). 



A distinct species, easily known fvom H. erythno-us, Ckll., 

 by the dark stigma and blue mesothoiax. The specific name 

 is in allusion to the dark blue colour. 



XLIV. — A Ncte on the Apparent Absence of Sexual Characters 

 in the Shell of Neiitina fluviatilis. By A. E. BOYCOTT 

 and J. W. Jackson (Victoria University). 



We give here the result of an enquiry into the possible 

 occunenee of difierences between the shells of male and 

 female Neridna fluviatilis. Our material has been derived 

 from two sources : — (1) the Preston-Lancaster Canal in the 

 neighbourhood of Barton, Lancashire, collected in June 



