A PPEXDIX— COL EOF TERA . 5 1 



Colombia or Ecuador, but are not generally known insects, and it is there- 

 fore higlily interesting to record a third species. It is easily known from 

 either of its congeners Ijy the mark on llic tliorax, wliicdi is appart-ntly 

 variable but shaped something like the letter M Avith the central V iilh-d up 

 with black. 



The genus is evidently allied to ('haulmjnathus, the head is wider in 

 front and with a distinct ch-jxnis. The claw j'oint of the tarsi is thickened 

 in a club-like node at the insertion of the claws which are simple in lioth 

 sexes. The Idack at the base of the elytra extends further in the female tlian 

 in the male. 



14. Silis ChimJ)ora:Mna, n. .sji. 



Hah. Southern side of Chimborazo, Ijelow the second camp (15,000 feet). 

 One specimen. 



Nigra, nitida, elongata, antennis fere simplibus, ore, mandibulis (apice 

 excepto) abdominis apice, in'othorace(|Ue flavo-ferrugineo, hoc margine antico, 

 disco(|ue postice nigris. Long. 6^- millim. ^. 



Mas, prothoracis laterilnis biexcisis, inter excisiones acute retrorsum pro- 

 ductis, et siiina nigra munitis ; segmento septimo ventrali fisso, flavo. 



This is a most interesting and remarkable insect allied to such sj^ecies as 

 Silis dUarrrafa, Gorh., Biol. Centr. Am., Vol. iii., pt. 2, p. 96, Imt difFerinfT 

 from anything pre\-iously known in the mode of distortion of the lateral 

 margin of the thorax into points and spines. The anterior black margin is 

 thickened near the front angles and abruptly terminated there, lielow it 

 springs the production of the middle of the sides — this 2)art is red and has a 

 sharp point of the same colour, Init gives rise to another longer Ijlack sj)ine 

 which is hairy. Below it the margin appears excised, the base is margined. 

 The elytra are black faintly sul)striate, opaque. For Figure see the accom- 

 panying Plate. 



Silis is a genus comprising some of the most curious forms among the 

 Telephoridre, the prothorax having its margin distorted and cut away at 

 or near the base, and often furnished with a spine-like pro(luction. The 

 seventh ventral plate is split and covers the eighth, the claws are siui]il(' in 

 the males. 



PlECTONOTUM, nov. gen. a« .Wc-- I i c' ; . 'TSm.^'--— "- 



Corpus parvum ; antenna' simplices, undecim-articulatfe corporis longi- 

 tudine. Palpi articnlo ultimo ovoido apice acuminati. Pronotum trans- 

 versum, disco convexo, medio Icviter canaliculato, margine parum elevato, 

 margine laterali subincrassato, ad angulos posticos leviter exciso. Pedes sat 

 longi. Elytra ampla, al)dominis apicem vix tegentia. 



H 2 



