290 CALIFORNIA ACADEMY OF SCIENCES. 



The character pointed out by LeConte and Horn in the 

 classification, and which consists of a sub-ocular ridge, 

 although probably of more or less value for the separation 

 of genera, would not serve for a general division into sub- 

 groups, because we have genera and species possessing this 

 ridge in all degrees of development, from Falagria, Colusa, 

 etc., where it is entirely absent, through such species as 

 Oxypoda insignia here described, where it is only present as 

 a very feeble ridge and toward the base of the head, being 

 entirely obliterated anteriorly, to Ilyobates and allied genera 

 where the ridge is remarkably strong, entire and very con- 

 spicuous. 



Another line of thought is opened by the contemplation 

 of this genus. The Stenini, it is well known, are related 

 more closely to the Aleocharini than any other group in one 

 important character, which is the mode of insertion of the 

 antennae upon the front. In the Stenini there is a remark- 

 able character to be seen in the structure of the dorsal seg- 

 ments of the abdomen, this consisting of a transverse ridge 

 which is produced posteriorly at three or four points in ele- 

 vated carinate cusps, and which forms one of the best char- 

 acters for the classification of the species. In Colusa, this 

 identical structure is to be seen, and also in a highly devel- 

 oped state, each dorsal segment having at base a straight 

 transverse ridge from which three long narrow elevated ca- 

 rina? project posteriorly; one of these is central and two, 

 longer than the central one, are lateral and very near the 

 elevated border; these ridges become abruptly very much 

 shorter on the fourth and fifth visible segments, although 

 nearly equal on the three basal ones. This rather remarka- 

 ble coincidence would appear to indicate that in one line of 

 descent the Stenini are very closely related to several forms 

 at present placed in the Aleocharini, and if we simply shor- 

 ten the basal joints of the palpi, we should have types of 

 these organs not unusual in that group. 



If the genus Neolara, described by Dr. Sharp (Biologia 

 Centrali- Americana I, p. 231) should in reality have five 



