214 Journal New York Entomological Society. [Voi.xn. 



The following table of the genera of the Mastinocerini, the two 

 Mexican ones included, is based on the characters given in the de- 

 scriptions of the genera. 



AntennK twelve-jointed. 



Joints four to eleven of antennae each with two short leaf-like appendages at 

 base, between these at middle a smaller dentiform process ; soldered to the 

 entire length of the twelfth joint is an appendage, similar in shape and texture 

 to the larger ones ; mandibles slightly arcuate, acute, not toothed ; last joint 

 of maxillary palpi gradually widening to apex, which is obliquely truncate, last 



joint of labial palpi oval Paraptorlhodius, n. g. 



Joints four to eleven biramose, twelfth simple ; mandibles strongly falcate ; last 

 joint of maxillary palpi gradually widening to apex, which is obliquely trun- 

 cate, last joint of labial palpi oval Ptorthodiiis, Gorh. 



Antennpe eleven-jointed. 



Antennal joints three to ten biramose, last joint of maxillary palpi subequal to the 



preceding, ovate ; eyes beneath nearly contiguous Euryopa, Gorh. 



Antennal joints four to ten biramose. 



Prothorax as long as wide, flanks acutely margined, maxillary palpi with 



last joint securiform IMastuiocerus, (Sol.) Lee. 



Prothorax as long as wide, flanks acutely margined only behind the middle, 

 obliterated in front ; maxillary palpi with the last joint long and cylin- 

 drical Ccnophengus, Lee. 



Tytthonyx ruficollis, new species. 



Red, antennae, palpi, elytra, wings, tibia; in great part, and tarsi black. Head 

 red, broader than long, deflexed, finely, densely punctate, eyes small, rounded, con- 

 vex, finely granulated. Antennae nearly as long as the entire body, black, first joint 

 more or less red, compressed, serrate, joints triangular, second shorter and narrower 

 than the third, outer joints narrower than the intermediate joints. Prothorax red, 

 transverse, truncate in front, broadly rounded behind, surface closely and finely punc- 

 tate, a fine median impressed line more or less distinct, and a few vague shallow im- 

 pressions, as in erytlirocephaluSf variable in distinctness. Elytra black, one half as 

 long as the abdomen, rounded at tip, slightly costate, faintly rugosely punctured. 

 Abc^omen red, legs black except femora at base. Length, 3.5-4 mm. 



Brownsville, Texas (S. Tomas, Esperanza Ranch). 



Types. — Four specimens. 



In erythrocephalus the antennal joints differ in the two sexes. 

 There is a little difference in the antennae in the specimens before me 

 but the last two abdominal segments are truncate at apex in all the 

 specimens. 



Cymatodera peninsularis, new species. 



Nearly of the form of (exaua, pale, head, apex of thorax, base, suture and a 

 lateral line, widened behind the middle black. Head black, mouth parts pale, some- 

 what sparsely punctured in front, more closely on the occiput ; antenna; stout, pale. 



