PTEROMALIDAE OF N.W. EUROPE 335 



proximal portion of the maxillary palpus is articulated to the maxilla, or whether it 

 merely forms a process of the latter, i.e., a structure which Kutter (1934 : 21, and 

 fig. 9) terms the " podium ". In penetrans (Kirby), microcera (Haliday), conjungens 

 sp. n., and paludum sp. n., the " podium " is definitely articulated to the maxilla ; 

 thus in these species the palpus is 4-segmented. On the other hand, in eximia 

 Haliday, chalybea Haliday, varicornis Haliday, and herbacea sp. n., the podium does 

 not seem to be distinctly articulated, hence the palpus appears to have only 3 

 segments. An attempt to define Macroglenes as having 4-segmented maxillary 

 palpi, and Pirene as having them 3-segmented, results in an arrangement which cuts 

 across other characters ; for example, conjungens and paludum would have to go in 

 Macroglenes although their males do not have the enlarged eyes characteristic of the 

 type-species of that genus. 



Thomson (1876 : 188) distinguished Macroglenes and Pirene as follows : 



a) Antennae funiculi articulis 2 primis annuli formibus. Scutellum 

 postice declive. Oculi maris rubri superne valde convergentes. 



Macroglenes. 



aa) Antennae funiculi articulis saltim 3 primis annuliformibus. Scutelli frenum 



horizontale. Pirene." 



The above characters suggested by Thomson do not work out any more consistently 

 than do the number of segments in the maxillary palpi. Two species (bouceki sp. n. 

 and conjungens sp. n.) which should go in Macroglenes according to Thomson's 

 definition of the antennal segments, have males with the normal eyes characteristic 

 of Pirene. The degree of slope of the scutellar frenum also cuts across other 

 characters. 



Finally, the male of decipiens sp. n. has large eyes as in Macroglenes, the male of 

 conjungens sp.n. has normal eyes as in Pirene ; but the females of these two species 

 are hard to distinguish. Thus there appears to be no really satisfactory way of 

 distinguishing the two genera, consequently I synonymize them. I have felt some 

 doubt as to which name to use. Macroglenes has priority, on the other hand Pirene 

 has been more often used and has also formed the basis of tribal or subfamily names, 

 therefore I have decided that its use would be more acceptable, and am applying to 

 the International Commission on Zoological Nomenclature for the retention of 

 Pirene. 



The earliest paper on the taxonomy of Pirene was that of Haliday (1833), in which 

 he described four species ; the descriptions, although brief, are excellent. His 

 revision of Pirene and Macroglenes (1844) contributed some valuable information. 

 Thomson's account (1876) of Pirene added nothing of real value, and in fact intro- 

 duced some errors because he wrongly associated the sexes of some species. Since 

 the time of Haliday there has been no critical revision of the species of Pirene 

 (including Macroglenes) and one is badly needed. In my keys to the species I have 

 utilized many characters which have previously been used ; but a new one, the 

 " pecten " (a row of specialized hairs on the inner aspect of the hind tibiae) is now 

 introduced. The head provides some good structural characters, but unfortunately 

 it very often collapses after death unless the specimens are specially prepared, and 



