230 FAUNA HAIVAIIENSIS 



narrower. The thorax is as long as broad. The shoulders of the elytra form a well- 

 marked denticle or angle outside the hind angle of the thorax. The legs are short. 

 The front tarsi of the male very little dilated. 



I have great pleasure in naming this interesting insect in honour of Mr R. C. L. 

 Perkins, who has been so remarkably successful in his entomological work in the 

 Hawaiian islands. It is very curious to find what appears to be an entirely precinctive 

 insect possessing a strongly marked specialisation that to some extent has an analogue 

 in two or three other of the Island forms {^Mecotnemis, Gnat holy mnaecuvi, Nesolymnaecitni) 

 that are only distantly, or not at all, related to it. I have, however, found that 

 Mesothrisciis progiiatlms apparently forms a lead to it. The insect appears to be 

 of great rarity. 



Hab. Maui (Perkins). Haleakala. 



Mecomenus, gen. nov. 



Partes oris graciles, mandibulae elongatae, tenues, parum curvatae. Prothorax 

 transversus sine setis erectis. 



The genus is established for M. koebelei and Anchoinemts putcalis Blk., two of 

 the rarest ot the Hawaiian Carabidae. It is allied by the elongate slender trophi to 

 Mecosto)iiiis, iiut in other respects is similar to Aletronienus. The sculpture of the tarsi 

 is that of such species as Metrojiiams epictirus. The section of Metrovienus to which it 

 is nearest is placed at the end of the genus, consisting of M. latifrons and calatlioides. 

 Meconieiiits has the broad base of the elytra in common with the section named of 

 Metromeniis. 



The genus like RIecostonms is confined to the island of Maui. 



(i) Jllecoiiienus koebelei, sp. nov. 



Latus, nigro-piceus, nitidus, antennis pedibusque testaceis ; prothorace transverso, 

 lateribus subrectis, angulis posterioribus perfecte rectis ; elytris sat profunde striatis. 

 Long. 7 — 8 mm. 



This very distinct species has a broad head, which is definitely constricted almost 

 immediately behind the eyes. The shoulders of the elytra are quite free. The thorax 

 is very shining ; the base is just perceptibly broader than the front, the posterior angles 

 are remarkably definite, and the sides near them much directed upwards. The elytra 

 are unusually broad, deeply striate, with the interstices quite flat ; the lateral groove is 

 yellow, and the tips are sometimes pale. 



In addition to the six examples of this species from Lahaina, there is an individual 

 without any locality label that I treat as a variety of H/. koebelei. It is narrower, and 



