COLEOPTERA 



227 



Readily distinguished from all the preceding species by the more convex interstices 

 of the elytra, and from the following species by the interstices appearing broad instead of 

 being angulate and therefore narrow at the summit. The seventh interstice is slightly 

 more elevated than the others, and there is also an extremely slight, increased elevation 

 of the filth. The base of the thora.x is not straight, and the hind angles are extremely 

 indistinct. The female has three setae on each side of the last ventral segment. 



The species is of considerable interest, as to a certain extent it connects the very 

 peculiar Kauai species of Mcsothriscus with those found on the central islands of the 

 group. The species to which it comes nearest is J\I. lauaiensis. It is apparently of the 

 greatest rarity. 



Hab. Kauai (Perkins). 



(12) ^Icsotliriscns optiinus, sp. nov^ 



Fusco-testaceus, antennis palpis pedibus elytrorumque margine laterali flavis ; 

 prothorace haud transverso, basin versus angustato, angulis obtusis ; elytris quasi 

 sulcatis, interstitiis fortiter sed inaequaliter elevatis, ad apicem haud truncatis, parum 

 sinuatis. Long. corp. ~\ mm. 



This specie.s — like so many other of the Kauai Carabidae — has the sculpture of the 

 elytra strangely abnormal ; the interstices are strongly elevated and angular at the top 

 so that the spaces between them form grooves, the true striae having disappeared : the 

 small impressions on the third interstice cause an interruption of the costa, breaking it 

 up more or less distinctly into elongate bullae, reminding one of the sculpture in the 

 genus Caralnis. 



M. optinius is distinguished from J/, altcriians by the larger size, more elongate 

 form and longer elytra, by the thorax narrowed behind, but not at all sinuate at the 

 sides, and by the obtuse and rounded hind angles of the thorax. Only two specimens 

 have been found. 



Hab. Kauai (Perkins). 



(13) Jlfesof/in'scns opcrciis, sp. nov. 



Piceo-testaceus, opacus, antennis palpis pedibusque flavis, elytrorum limbo testaceo ; 

 prothoracis angulis posterioribus obtusis; elyt.ns ad apicem profunde sinuatis interstitiis 

 alternis elevatis, crenulatis. Long. 7 mm. 



Distinguished by the peculiar sculpture of the elytra, these parts being dull, and 

 the more elevated part of each interstice wavy. It is larger than M. alternans, and 

 has the thorax different in form, being comparatively broader, more strongly narrowed 

 behind, with the hind angles more obtuse, and the sides more broadly explanate. Only 

 two specimens have been found. The female has only two setae on each side of the 

 ape.x of the abdomen. 



Hab. Kauai (Perkins). 



