Mr. Westwood's Observations on the Genus Derbe. l."> 



prima transversa recta obscuriore ; cellula inter venam analem marghu-inquc inter- 

 num serie duplici tuberculorum fuscorum. Ales posticae alb;r. venis paullo obscuriori- 

 bus. 



Another minute insect inhabiting the West Indies is the type of my sub- 

 genus Cenc/irea, which differs from all the rest in the very minute size of the 

 antennae, the very slightly produced front of the head, and the form and vein- 

 ing of the wings. The following are its characters : 



Cenchrea. IJ'cstw. 



Caput transversum; oculis magnis subtus emarginatis. Frona parum producta. Ocelli 2 

 sub oculos positi. Antenna minutee, in cavitatem circularem marginis lateralis pr©- 

 thoracis extensae, articulo primo annulari, secundo brevi subrotundato tuberculato, 

 dorsali. Rostrum ad basin pedum posticorum rxtensum, articulo penultimo Loogo, 

 ultimo minuto. Prothorax latus, lateribus dilatatis et ad angulum anticum scmicircu- 

 lariter elevatis. Mesothorax transversus, linea tenui media elevata. Abdomen breve 

 latum, lobis duobus terminatum. Pedes postici longi inermes. Aide anticac elongata . 

 angulo antico apicali valde obtuso, venis perpaucis longitudinalibus ; vena mediastina 

 (Tab. II. fig. 8 C, a) pone medium bifida, ramo postico ad apicem bifido ; vena | 

 costalis etiam pone medium bifida, ramo antico bifido (b*), ramo ordinario of cum vena 

 postcostali medianaque venis minutis transversis p et q conjuncto. 



Cenchrea dorsalis. Westw. 

 Tab. II. Fig. 8. 

 Pallida testaceo-fulva ; alis anticis flavescentibus margine interno fuseis apice 

 punctis duobus purpureis notato. 



Long. corp. lin. 1^. Expans. alar. lin. 5. 



Habitat in Insula S tt Vincentii, D. Guilding. In Mus. Dom. F. W. Hope. 



Caput pallidum, medio magis brunnescens ; oculi magni nigri. Thorax pallidus, vittis lon- 

 gitudinalibus brunneo-fulvis. Abdomen fulvo-brunneum, apice pallido pulveroso. Pedes 

 pallidi albidi. Aim anticae flavescentes, venis pallidis, margine externo lato fusco, strigfl 

 parva obliqua nigricanti pone medium costae, maculis duabus purpureis in margine api- 

 cali ; alas posticas albae, versus medium parum infuscatae, venaque furcata fusca, reli- 

 quis pallidis. 



t This ramus ordinarius, o, is as troublesome to determine, as the analogous branch emitted from 

 the middle of the extremity of the discoidal cell in butterflies. 



