624 Coleopterological Notices, IV. 



iient mandibles, the closest ally of Limnobaris appears to be Cen- 

 trinogyna, and, in this connection, it should be stated that in the 

 former the tip of the pygidium is occasionally exposed, especially 

 in the male. 



The basal joint of the antennal funicle is generally long, the 

 second decidedly short, becoming longer in the fifth group, and the 

 club varies considerably, being moderately robust, with a large basal 

 joint in the first group, but narrower and with a much shorter basal 

 joint in the others. There is also considerable variation in the 

 amplitude of the prosternal process between the coxae, the latter 

 being generally more or less remote, but occasionally narrowly 

 separated, again demonstrating the slight w^eight of prosternal 

 characters in some parts of the centrinide series. The prosternum 

 is usually flat, but in some species may be flat in the female and 

 deeply excavated in the male, and, in longula, is narrowl}^ impressed 

 along the middle in both sexes. 



The beak varies in structure to a noticeable extent in the several 

 subgeneric groups as detailed below, and in some of these sections, 

 the prosternal processes of the male are iavariabl}'^ wanting, while 

 in others they may or may not be present. In several species, 

 which happen to belong to all of the subgenera except the first, the 

 beak varies perceptibly in length in different individuals, necessitat- 

 ing some caution in separating the species. I have observed this 

 variation in length in pi^olixa, 7'ectirost.ris, ebena, and possibly 

 seminitens, also, as before stated, in Nicentrus lineicoUis. 



The five sections, into which it is convenient to separate our 

 species, may be outlined as follows: — 



Antenna! club more robust, with the basal joint large, constituting more than 

 one-half of the ma.-s and frequently more sparsely pubescent and sliining 

 toward base ; beak generally thicker, more strongly and evenly arcuate 

 and not tumid at base, the antennae inserted distinctly beyond the middle 

 in the male but more medially in the female ; prosternum always widely 

 separating the coxae and never armed in the male ; punctuation deeper, 

 denser and more uneven as a rule, the vestiture frequently more con- 

 spicuous and always uneven ; bo.Jy usually more or less rufo-piceous in 

 color and noticeably depressed I 



Antennal club generally narrower, densely pubescent throughout, the basal 

 joint much shorter ; body always intense black throughout, except in 

 the next subdivision, occasionally somewhat depressed. 

 Body oblong, moderately convex, densely, confusedly punctate and densely 

 but unevenly clothed throughout with oval whitish scales ; beak as in 

 the preceding section ; antennal club strongly annulate, the basal joint 



