Mr. T. V. WoUaston on the CoUoptera of St. Helena. 313 



Helena — where it was taken by the late Mr. Bewicke in 1860, 

 and subsequently in considerable abundance by Mr, Melliss. 

 It is conspecific with the insect characterized by Blanchard in 

 the entomological portion of Dumont d'Urville's ' Voyage au 

 Pole Sud sur les Corvettes 1' Astrolabe et la Zelee ' (p. 105, 

 pi. 7. f. 6) under the title of H. Sanctce-Helence. 



Apart from its numerous and strictly generic characters, the 

 H. arator may at once be known from the two species of 

 Mellissius by being rather smaller, darker, brighter, and more 

 cylindric, by its clypeus being more rugose, and bisinuated 

 (instead of truncate) in front, by its prothorax being un- 

 sculptured, and by the punctures of its elytra being distributed 

 in regular strise. Amongst other features, its antennaj are 10- 

 (instead of 9-) articulate, its propygidium is furnished with 

 two long file-like divergent bands for the purpose of stridula- 

 tion by friction against the inner surface of the apex of its 

 elytra, and its wings are fully developed. 



Genus 19. Mellissius (nov. gen.). 



Corpus crassum, supra nudum, subtus pills longis robiistis obsi- 

 tum : capite triangulari, clypeo apice truncate, necnon ibidem atque 

 subito in genis (ante oculos) plus minus incrassato recurve, fronte in 

 medio vel obsolete vel conspicue tuberculata : prothorace magno, 

 convexo, ad latera subsequaHter valde rotundato, in utroque sexu 

 nisi fallor (certe in masculo) simplici, nee antice impresso ; pro- 

 sternali loho (inter coxas anticas) brevi, piloso : scutello semicirculari- 

 triangulari : alis minutis, obsoletis : histriimentis stridulantihus aut 

 fere nuUis, aut propygidium pKculis brevibus tuberculisve trans- 

 versis ubique dense asperantibus. Antennae 9-art*: art", l'"" elon- 

 gato, robusto, subclavato, subflexuoso, 2"^° brevi transverse, 3"° 

 minore breviore, 4*°, 5'°, 6'° gradatim paulo crescentibus, reliquis 

 clavam magnam, foliatam, ovalem, 3-articulatam efiicientibus. 

 Lahrum clypeo absconditum. Mmidibulce cornese, robustse, subtri- 

 angulares, concavae, apice incurvae obtusse, extus setis lougissimis 

 instructae. Maxillarum lohus internus obsoletus, eseternus latus, 

 suboblongus, setisque longissimis ubique obsitus. Palporum tnaxil- 

 larium articulus ultimus obovato-oblongus, lahialium subebevatus. 

 Mentum (ligulam occultans) elongatum, subtriangulare, corneum, 

 pilis longissimis obsitum. Pedes fossorii, rebusti, subaequales : tibiis 

 anticis extus fertiter tridentatis, posteriorihus apice truncatis ciliatis : 

 tarsorum articulo hasilari subtriangulari, ultimo vnguiculis ajqnalibus 

 armato. 



The structural features of the group which I have enunci- 

 ated above bring it into close proximity to the Australian 

 genera CJieiroplatys and Isodon ; but a reference to the dia- 

 gnosis will show that it is abundantly distinct from them both. 

 Unlike them, also, it appears, at any rate in one of the two 



Ann. & Mag. N. Hist. Ser.4. Vol.'w. 23 



