1918.] 107 



fowl. I have had the advantage of discussing the matter with Dr. Heslop 

 Harrison of the Zoological Department, Durham University, and he 

 savs. hi Jift., " Your material thoroughly bears out your notion as to the 

 similaritv between it and the Andalusia n fowl. Still that is by far the 

 least important feature about it, for there are indications that it is also 

 an interesting case of sex-limited inheritance, of Avhich no case is known 

 in Coleoptera." Specimens taken wild are always open to mis-interpre- 

 tation, and experiment is absolutely neeessaiy to put the subject on 

 a Hrm basis, but the principles governing the case of the Andalusian fowl 

 seem to go a long way towards accounting for the rarity of ccdcaratus as 

 conijjared with ab. caesiiis and ab. macula fun. According to a note by 

 Faust (Stett. Ent. Zeit. 1890, p. 110), the occurrence of an unsealed 

 form amongst a scaled one is not uncommon in the genus Pht/llobius ; 

 he mentions three extra-British species in which it occurs and says that 

 the unsealed males appear less abundant than the females. P. caJcaratus 

 seems a fitting subject for fm-ther research, though breeding experiments 

 must necessarily be attended with some difficulty. 



Colesborne. 



April Wi, 1918. 



HALICTOXENUS ARNOLDI, AN UNDESCEIBED BRITISH STYLOPID. 

 Ci 11. C. L. PEKKiyS, M.A.. U.Sc-, f.Z.S. 



J^eugth of cephalothorax from the hind margin of the spiracle to the 

 middle of the front margin of the head in a straight line 'S-'O mm. ; width 

 across the spiracles '9-1 mm. Width across the spiracles 9-10 times the 

 width (where least) between the mandibles. Sides of cephalothorax notably 

 sinuate inwardly on a line with the opening- of the brood-chamber. 

 Colour yellowish brown, palest, sometimes quite yellow, on an area just 

 in Iront of the spiracles. Basal dark brown or blackish band extending in 

 front of the thoracic constriction to a line distinctly in front of the spiracles 

 on the two middle quarters of the width of the thorax ; from each side of the 

 apex of this dark area, a brownish vitta extends forward to the mouth of 

 the brood-chamber, and there these are connected by a more or less evident 

 transverse shade; the vittue gently converging from base to apex and enclosing" 

 at their base a transverse band of conspicuous pale spots. 



The two specimens described were first examined ui situ in their 

 hosts and appeared different in various res])ects, the one having the 

 s])iracles situated just within the lateral outline of the cephalothorax, 

 the other with the spiracles forming ]mrt of this outline. Subsequent 

 treatment, before mounting them on slides, did not change them in this 

 nor in other respects, and the differences observed were probably due to 



