1867.] 145 



Genus Exopholis. 

 Motschulsky (Etudes Entorn., 1859, p. 98). 



This genus, founded by M. Motschulsky upon Melolontha hypoleuca, 

 Wiedm., is separated from LeucophoUs, with which it had hitherto been 

 confounded, on account of the labrum having a central tooth ; a cha- 

 racter first pointed out, as I believe, by M. Lacordaire in his G-enera 

 des Coleopteres (vol. iii., p. 300, note). As the genus has never been 

 properly characterized, I have thought it well to do so now. 



Mentum sub-rectangular, toothed in the middle of the anterior 

 margin, anterior angles produced : two oblique ridges, springing 

 immediately below the insertion of the palpi, unite with a third (part 

 of which forms the central tooth in the anterior margin) and form an 

 inverted Y- Maxillae short, with five or sis blunt teeth on the inner 

 side. Mandibles acuminate, with three or four blunt teeth on the 

 inner side. Labrum with a central acute tooth, slightly emarginate 

 on either side. Apical joint of the labial palpi equal to the two pre- 

 ceding joints together. Head sub-quadrate ; clypeus with the angles 

 rounded, the anterior margin very slightly reflexed. Antennae 9-jointed ; 

 first joint elongate, second sub-ovate, third and fourth joints elongate, 

 sub-equal ; the three last joints forming a short ovate club. Thorax 

 transverse, with the sides more or less rounded, anterior angles acute, 

 posterior obtuse or sub-rectangular. Elytra oblong, costate. Anterior 

 tibiae with two or three teeth, and with a spur. Posterior legs as in 

 LeucophoUs. Mesosternum but little prolonged. The upper surface of 

 the insect is almost destitute of scales. The under-side covered, except 

 the suture of the mesosternum and abdomen, with fine yellow or white 

 scales, especially the sides of the abdomen. 



M. Motschulsky describes {he. cit.) a species of this genus (Sx. 

 Birmannica) which appears only to differ from M. hypoleuca in its 

 greater size, broader and more oval form ; the punctuation and rugosity 

 being stronger on the thorax and less on the elytra ; the anterior angles 

 of the thorax more prominent ; and the prolonged part of the anterior 

 tibiae narrower and not dilated at the extremity. 



Ex. Birmannica may possibly prove to be only a local variety of 

 hypoleuca. M. Motschulsky seems only to have seen a single specimen. 

 I have before me a number of specimens, all of which I believe to be 

 hypoleuca, from Tenasserim, Penang, Java, and Borneo, varying in 

 colour from testaceous to dark chestnut-brown, and from 7 to 13^ lines 

 in length, with every intermediate degree. There is some diversity of 

 form even in those from the same locality ; the specimens from Borneo 

 (with one from Sumatra), however, have the sides of the thorax less 

 rounded than is usual. 



