Mr. Westwood's Observations on the Genus Derbe. 15 



prima transversa recta obscuriore ; cellula inter venam analem marginemque inter- 

 num serie duplici tuberculorum fuscorum. Alee postiese albae, venis pauUo obscuriori- 

 bus. 



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

 genus Cenchrea, 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. fVestw. 

 Caput transversum ; oculis magnis subtiis emarginatis. From pariim producta. Ocelli 2 

 sub oculos positi. Antenrue minutae, in cavitatem circularem marginis lateralis pro- 

 thoracis extensse, articulo primo annulari, secundo brevi subrotundato tuberculato, seta 

 dorsali. Rostrum ad basin pedum posticorum extensum, articulo penultimo longo, 

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

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

 latum, lobis duobus terminatum. Pedes postici longi inermes. Alee anticae elongatae, 

 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 post- 

 costalis etiam pone medium bifida, ramo antico bifido (6*), ramo ordinario of cum vena 

 postcostali medianaque venis minutis transversis p et g conjuncto. 



Cenchrea dorsalis. Westw. 



Tab. II. Fig. 8. 



Pallid^ testaceo-fulva ; alis anticis flavescentibus margine interno fuscis apice 



punctis duobus purpureis notato. 

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



Habitat in Insula S*' 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 anticse flavescentes, venis pallidis, margine extemo lato fusco, strig^ 

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

 cali ; alae posticEe albse, versus medium pariim infuscatae, venaque furcate 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. 



