458 Mr. Gilbert J. Arrow's Classification of 



Four specimens were collected by Mr. W. H. Rosenberg 

 in November 1896, and, like the preceding species, formed 

 part of the collection of the late Mr. Alexander Fry. It 

 is a form very easily recognised by the strong spin(nis 

 processes with which the ocular ridges are armed. It is 

 smooth and almost entirely devoid of hair. The prothorax 

 is long and its front augles sharply pointed. The elytra 

 are less strongly sculptured than in any other species 

 known to me, the punctures in the striae being not coarse 

 at the sides and barely traceable dorsally. 



Tetraracus centralis, sp. n. 



Elongatus, parum convexus, antennarura clava articuhs tribus 

 ultimis longibus duobusque praecedentibus niulto brevioribus com- 

 posita, clypeo antice 4-dentato, dentibus interioribus minutis, ap- 

 proximatis, exterioribus validis, coruu froiitale minuto, carinato, 

 carinis frontalibus integris, arcuatis, spatium magnum rugosum 

 includentibns, angiilo obtnso, tuberculato ; protliorace vix transverso, 

 antice angustato, angulis anticis fere rectis, lateribus grosse irregu- 

 lariter punctatis, sulco marginale angusto, antice valde sinuato, 

 dilatato, grosse punctato ; scutello postice impunctato ; elytris 

 profunde striatis, interstitiis convexis, striis fortiter punctatis, 

 liumeris parce flavo-birsutis ; mesosterno glabro, utrinque profunde 

 fossulato, metasterno medio parce minute punctato, lateraliter grosse 

 baud numerose punctato. 



Long. 19 mm. 



Hah. Costa Rica, Volcan de Barba (1600 metres). 



TctraracMS is very closely related to Pao:illus, from which 

 it is unnaturally separated by Kuwert on account of the 

 existence of two minute projections at the middle of the 

 clypeal margin. The form of the club of the antenna in 

 the present insect is shared by only two other described 

 species of Passalidas, although others exist. The three 

 terminal lamellae are long, and the two preceding them 

 about half their length, so that even when the club is con- 

 tracted a distinct break occurs. T. centralis is smaller and 

 more elongate than the other two species. The prothorax 

 is rather narrow, distinctly tapering towards the front, 

 with rather sharp front angles. The elytra are moderately 

 flattened, with closely punctured striae and there are a 

 few short hairs at the shoulders. 



Two specimens have been sent to the museum by Mr. 

 P. Biolley. 



