18/8.] HEMIPTERA OF ST. HELENA. 



463 



Aphides and Cocci. Of the 30 determinable species in Mr. Wol- 

 laston's collection 5 species — 



Nabis capsiformis, Germ., 



and 

 Issus coleoptratus, F., 



Nezara viridula, L., 

 Lyctocoris campestris, F., 

 Lygus apicalis, Meyer, 



have been probably introduced since the island was discovered. 

 The species which I have referred to Nysius thymi, Wolff, may also 

 be an introduction ; but I am more inclined to consider it a native. 

 The remaining 24 species seem to be all peculiar to the island ; 

 and for the reception of 10 of them I have been obliged to create 7 new 

 genera and 1 new subgenus. Mr. Wollaston has not, unfortunately, 

 recorded for the Hemiptera, as he has done for the Coleoptera, the 

 special modus vivendi of each species ; but as the particular part of 

 the island inhabited by each was briefly noted by him, I have been 

 careful to give all the information I can. 



Megarhaphis, gen. nov. 

 Genus Macrorhaphidi valde affine. Caput apice subtritncatum, 

 lobis eequilongis. Rostrum 'articulo 2° 4°que subcequilongis, sin- 

 gulatim 3° longioribus. Thorax marginibus lateralibus subcal- 

 losis, vix tranversim rugosus. Scutellum parte apicali retrorsum 

 angustata, frenis ultra medium scutelli continuatis. Carina 

 mesosternalis mediocris, nee lata nee sulcata. Venter spina 

 basali longa compressa armatus, apud marem maculis sericeis 

 hand instructus. Femora antica subtus apicem versus spina 

 ■ parva armata. Tibia antica vix dilatatce. Membrana costis 8 



instructs. 

 There is no doubt that Megarhaphis is closely allied to Dallas's 

 genus Macrorhaphis ; but it seems to me that the characters pointed 

 out above are of importance sufficient to necessitate the creation of 

 a new genus for the species described below. The difference in the 

 comparative proportions of the joints of the rostrum, the narrow and 

 unfurrowed keel of the mesosternum, the absence of the two silky 

 spots on the venter of the male, and other points will at once dis- 

 tinguish Megarhaphis from Macrorhaphis, 



1. Megarhaphis wollastoni, sp. n. 



M. elongata, rufo-brunnea, rude et dense nigro-punctata ; thoracis 

 angiitis lateralibus prominulis obtusiusculis ; pedibus corpore 

 concoloribus ; antennis paullo pallidioribus ; capitis lineis 2 lon- 

 gitudinalibus ocellos includentibus, marginibus tyli, vitta centrali 

 capitis subtus sternique, maculis marginalibus dorsi abdominis, 

 nebulisque ventris nigris ; spina basali ventrali ad apicem testacea ; 

 membrana brunneo-fusca. Capitis lineis 2 longitudinalibus inter 

 ocellos ad apicem currentibus, margine interiore orbitce, tyloque, 

 pronoti callis irregularibus prope marginem anticum, necnon 

 carina longitudinali angusta, scutelli linea apicali longitudinali 

 subelevata, corii spatiis irregularibus {una ad medium, altera prope 

 apicem), haud vel vix punctatis ; sterna ventreque minus dense 



