On a remarkable new Ball-roUiruj Beetle. 4;ili 



cell almost pointed on tlic raliiis, the seeond transverse 

 rui)ital nervure curved. Apex of the radial cell a little 

 I'lirther from the apex of the win-^ than from the i\pex of 

 the stigma. 



Hub. Ilouei Sai, Ilant Mekong, June G-10, 191S. 1 S -_ 

 Possibly a form of AgaUiis maculipennis, 13riille, whieh it 

 resembles in colour, but the second fnscoiis spot on the fore 

 wing is absent in the present species. Urulle's description 

 is not snflieient to in.iicate whether his species should be 

 placed in Euagathis or Disuphnjs. 



XL! 1 1. — A remarkable neio Bill-rolUng Beetle 

 {family Scarabfeidie). Hy Gilbert J. AuROW. 



. (PiiblislieJ by permission of the Trustees of tlio IJritish .Museum.) 



A SINGLE specimen of the e.Ktraordinary insect here repre- 

 sented, bt'iuing no label to record its origin or hal^itat, was in 

 the colled ion of the late B. G. Nevinson, reeentlv ])reseiited 

 to the Biitis'.i Museum by his son. Probably, like its nearest 

 allies, it inhabits the western part of Southern Afrien, possibly 

 the Bihe district of Angola, from which Mr. Nevinson 

 neeived other interesting beetles. The specimen is a male, 

 and the great enlargement of the fore legs is no doubt 

 distinctive of that sex. The enormously thickenei front 

 femora seem to indicate great muscular j)ower, and the 

 strangely shrunken intermediate legs appear more .singular 

 by contrast. The insect i.s a striking exatnple of speciali- 

 zation by successive atrophy of its members. The front tarsi 

 have disap[)eared in all the ball-rolling Scarabajidte ; the 

 wings also have gone in the present genus, uiid here we seem 

 to be advancing towards a reduction in the number of legs 

 from six to four. 



I retrain from establishing a new genus for this species in 

 view of the unsatisfactory character of several of those at 

 present reeognizetl in the group. I can find no sufficient 

 rt-'ason for .separating Pac hg so ma lunl Mnematlum. Although 

 M. sile)iiis,(jcii\yy has the middle eo\a3 apart, the type-species, 

 M. rilchii, has not, and the features relied upon by Macleay 

 for its severance from Pachgsoma have been found to have 

 no importance. Similarly, there seems no a letjuate ground 

 for .separating Mnem itidium trom Sbasteos. 



Mnematiuin cancer, sp. n. 



Nigrum, nitidum, glabrum, corpus dcpressnm, latissimum, capito 

 antice (J-dentato, supra hand dense tuberculato, prouoto hie et 

 illic minute punctato, laterilnis serratis, basi leviter sinuato, 



