Royal Physical Society. 83 



Three species from Algeria, C. marginicollis, C. celer and C. 

 rufipennis, have been described in 1849 by M. Lucas in the ' Ex- 

 ploration de FAlgerie/ 



One species, C. australis, from Van Piemen's Land, has been 

 described by Erichson in Wiegmann's 'Archiv fiir Naturge- 

 schichte/ 1842. 



The North American species hitherto described are C. basi- 

 laris, C. opacus and C. simplex, described by Say in the Journal 

 of the Academy of Philadelphia, vols. iii. & v. ; C. Spenciana de- 

 scribed by Kirby in the ' Fauna Bor. Americ/ ; C. cadaverinus, 

 C. Frankenhauseri, C. cryptophagoides, C. brunnipennis, and C. 

 luridipennis described by Mannerheim in the ' Bull, of the Imp. 

 Soc. of Mosc/ in 1843, 1852 & 1853; C. terminans described 

 by Leconte in Agassiz's ' Lake Superior/ and C. clavicornis, C. ca- 

 lifornicus, C. strigosus, C. consobrinus, C. oblitus and C. parasitus. 

 described by the same author in the ' Proceedings of the Aca- 

 demy of Philadelphia/ 1853. 



So much for the past history of the genus. We shall now 

 proceed to the examination of the different species seriatim. 



In doing so I shall first take the European species of each 

 section, and then give the descriptions of the exotic species. I 

 shall not attempt to intercalate the latter among the European 

 species, because there are a number which I have not seen. I 

 shall content myself with classing them according to their 

 geographical distribution. 



Genus Catops. 



Mentum square, transverse, a little narrowed in front. Ligula 

 of the breadth of the mentum at its base, widened and deeply 

 emarginate in front. The internal lobe of the maxilla terminated 

 by a corneous nail or hook. The maxillary palpi decidedly larger 

 than the labial ; their third article formed like a reversed cone, the 

 fourth much more slender, conic and acuminated* The third article 

 of the labial palpi oval, a little longer than the second. Man- 

 dibles short, furnished with a molar tooth at their base, arched, 

 sharp at the end and unidentate before their summit. Labrum 

 short, rounded, and a little sinuated in the middle in front. 

 Head declining, obtuse in front. Eyes nearly rounded, moderate 

 in size and not prominent. Antenna at least of the length of 

 the thorax ; their first six articles of variable length, subcylindric, 

 the last five forming a club, which is sometimes so elongated and 

 slender as to be scarcely observable, and sometimes very distinct ; 



