H. C. FALL. 139 



Synopsis of the genus is erroneous in several important par- 

 ticulars. He describes the thorax as without strigosity, the 

 hind angles without trace of carina and the elytral apices not 

 serrulate, none of which statements are correct. In these 

 respects knausii is in accord with the type, and the only dif- 

 ferences noted aside from color were the apparently some- 

 what shorter antennas and the slightly better marked carina 

 of the hind angles of the prothorax in the latter. 



LAMPYRID^E. 

 PLATEROS Bourg. 

 P. roseimargo n. sp. 



Slender, nearly four times as long as wide, black, sides of prothorax 

 rather widely, apex more narrowly margined with rose red. Antennae 

 (o") feebly serrate, nearly half as long as the body; third joint tri- 

 angular, as wide as long, about three-fifths as long as the fourth and 

 quite as wide ; fourth about twice as long as wide. Prothorax a little 

 more than two-thirds as long as wide, widest at base, sides feebly con- 

 vergent for a short distance from base, then more strongly so, sinuate 

 each side of the rather narrowly rounded apex ; median line not cari- 

 nate in front, channeled behind. Elytra five times as long as the pro- 

 thorax, reticulation rather fine but distinct ; costaaa fine, the alternate 

 ones just visibly more prominent. Length, 6 mm. ; width, 1.6 mm. 



Santa Rita Mountains, Arizona. One cf, collected by 

 Prof. Snow. 



P. coccinicollis n. sp. 



Black, prothorax bright rose scarlet, with or without a small postero- 

 median black spot. Antennae ( 9 ) as long as half the body, third 

 joint triangular, slightly wider than long, nearly or quite equal in 

 width to the fourth joint, the latter oblong, narrowed at base, one- 

 half longer than wide and nearly twice as long as the third ; fifth joint 

 similar to but slightly shorter than the fourth, following joints sub- 

 equal in length to the fifth and gradually narrower. Prothorax seven- 

 tenths as long as wide, sides nearly parallel basally, broadly evenly 

 arcuate around the front, the outline only very slightly more promi- 

 nent at apex ; median line feebly subcarinate in front, impressed poste- 

 riorly ; margins moderately reflexed. Elytra nearly three and one- 

 half times as long as the prothorax, feebly rather indistinctly reticu- 

 late, the costas fine and equal. Length, 7\ mm. ; width, 2\ mm. 



Described from three female specimens taken at Beulah, 

 New Mexico (type), and Boulder, Colorado. At once separ- 

 able from all our previously described species except the 



TRANS. AM. ENT. SOC, XXXVI. JUNE, 1910. 



