118 



edges of the céphalothorax". This sentence seems to be in con- 

 tradiction with the following lines : p. 95. „The part of cépha- 

 lothorax situated before the constriction corresponds probably to 

 the head PI. 1, fig. 11 a. and the part behind this constriction 

 to the thorax. PI. I, fig. 11 b." The passage quoted probably de- 

 termined Mr. W. D. Pierce to measure the breadth of head at 

 this constriction i. e. in front of the genital slit, and not at the 

 ends of the curved line bordering this orifice, as he did in the 

 other species of the genus Halictoxenos. This was the reason 

 why the relation of the breadth of the head to the distance 

 between the spiracles he obtained ^; while usually this ratio is 

 about ^. This result suggests some doubts as to the value of the 

 subgenus Halictostylops Pierce (formerly genus) and renders 

 necessary to find for it new systematic characters. 



Triungulinid larva. PI. II, fig. 3. Light brownish. L. 0,15 to 

 0,16mm.; the maximum breadth 0,05 mm.; length of stylet 0,09 mm. 

 Head transverse with brown eyepatches on sides. The mouth 

 parts are indistinct. Fig. 3. Two ocelli ; this seems to be a ge- 

 neric character as H. Nassonovi Pierce has also two ocelli 

 (errata to W. D. Pierce 09 p. 113 „Eye patches showing three 

 small lenses" — "Jwo only in Nassonov's description and illu- 

 strations; see N. Nassonov 1893). It is curious to mention that 

 Mr. A. Handlirsch (in Handbuch der Entomologie, Bd. . III. 

 Lief. 11/12 p. 720) gives an illustration of a larva of Halictosty- 

 lops Spencii Nass. Fig. 591 after Nassonov {"= Halictoxenos 

 Nassonovi Pierce); but being a diagrammatic reproduction of 

 Nassonov's fig. 9, pi. I. it is in reality a side view of a larva 

 of Sty lops melittae N ass. (not Kirby). Legs four jointed; coxae 

 covered with hairs ; femora short, thickened at the base, distally 

 armed with a long spine; four fore tarsi flattened, slightly ex- 

 panded to the rounded end. The hind tarsi acute. The episternal 

 sclerites with a few minute spines. Sternal sclerites ending with 

 four long spines. Thoracal segments only dorsally, abdominal ones 

 dorsally and ventrally with terminal fringe of spines. The long 

 spines irregularly alternate with one or two small ones. The ninth 

 segment ventrally with two rounded tubercles bearing stylets. 



The two European species of Halictoxenos known at present 

 can be easily distinguished by means of the following key: Fe- 

 males and triungulinid larvae. 



