284: Mr. R. E. Turner on Fossorial Hymenoptera. 



between them. While in the genus Polydesmus (20 body- 

 segments) most of the species show gonapods more or less 

 deeply divided into two distinct processes, the great majority 

 of the Brachydesmus species (19 body-segments) possess 

 gonapods either undivided at all or but slightly notched, as 

 seen in the adjoined sketches. It is even possible to trace 

 still further homologies in the details of the telopodite. 

 The posterior transverse ridge, for instance, is bej^ond doubt 

 homologous with the pulvillum-bearing wart of the adult 

 gonapods, and the anterior process with the secondary or 

 tarsal ramus. 



It is therefore unquestionable that we have to deal with 

 the case of a larva provided with almost adult male copulatory 

 organs. Such a structure is frequent and* even normal with 

 Diplopods of archaic type, such as Colobognatha or Spiro- 

 boloidea ; but that it should be witnessed in the highly 

 specialized Polydcsmoidea is certainly most striking. 



This ease is, moreover, of considerable importance if viewed 

 with reference to the part assumed by Neotenia in the 

 evolution of Myriapods, as I have just propounded in a 

 pamphlet now in the press (" Travaux du laboratoire maritime 

 de Cette "). 



XXXTL — Notes on Fossorial Hymenoptera. — XXXIII. On 

 new Ethiopian Species of Psammocharidae. By Rowland 

 E. Turner, E.Z.S., E.E.S. 



The study of the Psanmiocharidse is much complicated by 

 the strong sexual dimorphism in many groups, by the 

 absolute unreliability of colour distinctions in many species, 

 and by the variability of neuration characters in the same 

 species within certain limits. As the sexes are very rarely 

 taken coupled, certainty as to the pairing is extremely 

 difficult where the sexual dimorphism is strongly developed, 

 but in some cases the neuration affords a good clue. The 

 points of neuration most liable to variation arc the point cf 

 origin of the cubitus of the hind wing and the comparative 

 length of the abscissa; of the radius ; small variations in 

 these points should not be considered as necessarily of 

 specific importance. Colour distinctions are of far less 

 importance, in Hemipepsis glabratus, King, the fulvous 



