1913.] 57 



THREE NEW SPECIES OF ATHETA. 

 BY NORMAN H. JOY, M.R.C.S., F.E.S. 



IMost students of the genus Atheta must have been puzzled over 

 the apparent variability of A. melanocbra, Th. (volans, Scrib.), and have 

 suspected that more than one species was really included under this 

 name. I have now examined the (^ genitalia of a large number of 

 specimens of this species, and have found four distinct forms of 

 tedeagus. There is little doubt as to which of these species the name 

 melanocera applies. In Thomson's original description the legs are 

 described as being fusco-testaceous in colour with darker posterior 

 femora, and in only one of the species are the legs so coloured. To save 

 confusion I still regard halophila, Th., and volans, Scrib., as synonyms of 

 melanocera, and describe the other three forms as new to science. 

 The (^ of all four species may be recognised from the $ by the broader 

 and more rounded under plate of the sixth free segment of the hind 

 body, the upper plate in both sexes being simply rounded. In the ^J 

 of A. elongatula, G-rav., the under plate projects further beyond the 

 upper plate, the hind margin of which is slightly sinuate in the middle 

 in both sexes. The sedeagus in the four species under review is a com- 

 paratively large organ. In A. elongatula the ^ genitalia are of an 

 entirely different structure, the median lobe being very small. As will 

 be seen from the following descriptions there are external characters 

 which will help in the identification of the species. These are generally 

 only comparative differences, but they are distinct enough, at any rate 

 in fresh examples. Very old specimens become much faded so that 

 the colour of the legs cannot be relied upon. There appears to be no 

 difference in pu.nctuation or the shape of theantennse. I have thought 

 it best to give a rather detailed description of A. melanocera, so that 

 the comparative differences in the other species will be more compre- 

 hensible. 



A. MELANOCERA, Til. 



Black, elytra sometimes pitchy brown, apex of sixth free segment of hind 

 body sometimes yellowish, antemue black, first two joints pitchy, legs fuscous 

 yellow, femora slightly darker; fore-parts rather dull, finely bvit distinctly 

 shagreened ; head much narrower than elytra ; antennae with f oiirth and fifth 

 joints elongate, penultimate joints quadrate or slightly transverse; thorax 

 slightly narrower than elytra, rather strongly transverse, broadest close to 

 anterior angles and very slightly contracted behind ; elytra 1\ times longer than 

 thorax ; basal segments of hind body rather closely, apical segments diffusely, 

 punctured ; median lobe of sedeagus with two right-angled bends and pointed 

 at the apex (Pig. 1). Length 3 — 3.5 mm. 



