Mr. Westwood's Observations on the Genus Derbe. 9 



Diospolis. Westin. 

 Lydda, Westw. in Proc. Linn. Soc, p. 84. 

 Rostrum brevius quam in Derbe typicali. Antenncc breves. Ala anticaj longissinue, an- 

 gustissimae, apice rotundatae. Directio venarum anomala ; regionc ven« medians mini- 

 ma (Tab. II. fig. 1 c.) aut potius ejus rami *** in ramos vena? postcostalis (fig. 1 b.) 

 transformati ; ramo littera o indicato ramo o subgeneris Mysidids (meo judicio) analogo. 



DlOSPOLIS ELONGATA. 



Tab. II. Fig. 1 . 



Derbe elongata, Fabr. Ent. Syst. iv. 34. Syst. Piez. p. 82. 



Long. corp. lin. 2. Expans. alar. lin. 8. (mens. AngL). 



Habitat in Nova Hollandia. In Mus. Soc. Linn. Lond. 



Fulvo-flavescens. Caput concolor pallidum ; oculi fusci. Antenna pallida?. Rostrum ob- 

 scure sanguineum. Cot/are flavo-fulvescens utrinque pone oculos rufum. Mesothorax 

 flavo-fulvescens, lineis duabus tenuibus mediis postice coalitis lateribusque rufis, scu- 

 tello pallido lateribus rufis. Abdomen fusco-fulvum, linea media punctisque in lineis 

 quatuor dispositis pallidis ; genitalia pallida. Aloe anticae pallide luteo-fulvae, margine 

 interno pallidiore, venis transversis venarumque longitudinalium basi apiceque fusco- 

 tinctis ; alae posticaa parvae pallidiores. Pedes concolores, apice tarsorum fusco. 



In the Transactions of the Royal Academy of Sweden for 183/ (' Kongl. 

 Vetenskaps Academiens Handlingar,' Holm. 1838) M. Boheman has published 

 a memoir, entitled * Observationes in Derbe genus una cum specierurn quin- 

 que novarum descriptionibus.' The five species described in this memoir are 

 inhabitants of Sierra Leone, and materially differ from the typical species of 

 Derbe as well as from the other subgenera above described, with none of 

 which, indeed, was M. Boheman acquainted. These five species were divided 

 by M. Boheman into two sections, which the author suggested might easily be 

 considered as subgenera. In the elongated form of the wings they agree with 

 the typical species of Derbe; but the paucity of the veins gives them a nearer 

 relation to Mysidia, and especially to Diospolis, from which genera, however, 

 both the sections are quite distinct. 



The following characters distinguish the first of M. Boheman's sections 

 from the other subgenera of the group : I propose to name it 



vol. xix. c 



