58 R. W. CROSSKEY 



few species previously placed in Hamaxia and also in Hamaxiomima Verbeke (for 

 the latter nominal genus from Africa is also indistinguishable from the redefined 

 Palpostoma). With this synonymy established it is clear that Palpostoma becomes 

 a clearly defined Old World genus of real homogeneity that is distinguished from 

 other Palpostomatini by the bristled prosternum. The principal generic characters 

 for Palpostoma as here redefined are as follows. 



Palpostoma Robineau-Desvoidy. Head with eyes strongly approximated, often holoptic 

 in g, usually dichoptic but sometimes holoptic in 9- Face sunken and warped forwards 

 to epistome. Epistome not conspicuously narrowed and at most only slightly elongated 

 in its dorsoventral axis. Vibrissae present. Labellae with distinct palpiform processes 

 of varying size. Prosternum setulose (each side with one or more downwardly directed 

 bristles or strong hairs). Propleuron bare. Two post ia setae (except in aldrichi with one). 

 Scutellum with two pairs of marginal setae (basals and strong crossed apicals). Wing with 

 cell R b open to short-petiolate (petiole at most only slightly longer than r-m). Bend of 

 vein M without appendix. Lower calypter small and evenly rounded on the hind margin, 

 strongly diverging from the scutellum. 



It will be observed that Palpostoma aldrichi Hardy differs from other species 

 by the possession of one instead of two post ia setae, a fact that it is necessary 

 to emphasize because aldrichi is the species that Aldrich (1922) considered to be 

 the type-species of Palpostoma and upon which he based his generic description 

 (in which he cites one post ia seta as diagnostic character). Palpostoma Robineau- 

 Desvoidy was based originally upon a single species, P. testaceum Robineau-Desvoidy 

 from 'Nouvelle-Hollande', of which the type is lost and the identity therefore 

 uncertain. Aldrich (1922) determined as testaceum a species from northern Queens- 

 land that possesses only one post ia seta and that parasitizes Lepidoderma albohirtum 

 Waterhouse (now called Dermolepida albohirta), but Hardy (1938) considered that 

 Aldrich was in error because the beetle host occurs in a part of Australia from 

 which Robineau-Desvoidy is most unlikely to have had material. Hardy therefore 

 concluded that Aldrich misidentified testaceum, and that the species dealt with by 

 Aldrich under this name was actually unnamed: Hardy therefore described it as 

 P. aldrichi. Although Hardy's view is conjectural it appears to me that he was 

 almost certainly correct. The true testaceum Robineau-Desvoidy was almost 

 certainly one of the more typical Palpostoma species with two post ia setae that 

 occurs in New South Wales (the probable provenance of Robineau-Desvoidy's 

 specimen) , and Hardy suggested that it is perhaps the species that Malloch described 

 as P. apicale. This is quite likely true, but it appears even more possible that it 

 might be the species that Malloch described as P. subsessile, because in this species 

 the petiole of cell R 5 is rather short and Robineau-Desvoidy's description (with 

 the wording 'petiolee au sommet') rather suggests a very short petiole. At the 

 present time it cannot be decided to which species the name testaceum should be 

 applied, as the whole complex of Palpostoma in Australia badly needs revision, but 

 it is best to conclude (in agreement with Hardy) that it does not apply to Aldrich's 

 'testaceum" (=aldrichi) , with its improbable provenance and atypical characteristics 

 (which are strongly apomorphic in relation to the main body of Palpostoma species). 

 Neotype designation is desirable in this case to fix the identity of testaceum but I 



