18 



NEPIDjE, 



are subject to considerable variation in colour and minor struc- 

 tural characters. Ferrari subjected tlie genus to a rigorous 

 revision, and proposed the recognition of many distinct species, 

 which I at least, and Montandon also, have been unable to 

 differentiate. Considei'able value has been placed on the ab- 

 dominal appendages for tlie differentiation of species, but these 

 are of a very fragile character and seldom complete in Museum 

 specimens, A good superficial differential character appears to 

 exist in the colour of the upper surface of the abdomen, and 

 this taken in a broad and not too narrow sense is undeniably 

 helpful. 



With a considerable number of specimens passing through my 

 hands, including Montandon's cotypes and identified species, I 

 cannot recognize more than three species as found in British 

 India. Their size, combined with the colour of the abdomen 

 above, apart from other structural characters, renders their 

 separation a matter of little difficulty. 



148' 



Laccotrephes robustus, Stdl, Ofv. Vet.- Ak. Fork. 1870, p. 706: 

 Ferrari (Nepa), Ann. Jiofmus. Wien, iii, p. 182 (1888) ; 3Ion- 

 tand. Ann. Mus. Civ. Gen. xxxvii, p. 376 (1897). 



Tar. pfeiferiae, Ferrari (Nepa), Ann. 

 Hofmus. Wien, iii, p. 187 (1888) ; 

 Montand. Ann. 3Ins. Civ. Gen. 

 xxxvii, p. 376 (1897). 



Tuscous or piceous ; abdomen 

 above sanguineous or subsangui- 

 neous, its apex fuscous ; femora 

 very obscurely palely annulate ; 

 wings vitreous, with a slightly bluish 

 tinge ; abdominal appendages about 

 equal in length to, or a little longer 

 than, the body ; hemelytra sub- 

 parallel. 



Length 36 to 44 ; breadth between 

 post, pronotal angles 12 to 12^ 

 millim. 



Hah. Naga ' Hills {Chennell). 

 Burma ; Karennee (Feci). — Siamese 

 Malay States (Skeat Exped.). Perak 

 {colJ. Dist.). Philippines {Semper). 

 Fig. 13. — Laccotrephes rohus/ns. 



1488. Laccotrephes ruber, Linn. (Nepa) 3his. Lud. Ulr. p. 165. 2 

 (1764) ; Mayr, lieise Nov., Hem.j,. 188 (1866) : &tal (Lacco- 

 trephes), ILejn. Fahr. i, p. 135 (1868) ; Montand. A^in. Mus. 

 Civ. Gen. xxxvii, p. 376 (1897). 



Nepa giossa, Fahr. Ent. Syst. iv, p. 62. 5 (1794) : Ferrari, Ann, 

 Hofmus. Wien, iii. p. 177 (1888). 



Nepa flavoveuosa, Dohrn, Stett. ent. Zeit. xxi, p. 409 (1860) ; 



