AMERICAN COLEOPTERA. 131 



and Coacinia. Thp8e with Nomiuif seem to represent three tirnups in 

 the tribe. Coscinia lias very little relationship with Sluf/oim execjit a 

 slight resemblance in a.spcct. All the genera of this tribe as thus detined 

 have a. well marked elytral plica internally, a character sufficiently re- 

 stricted in its distribution to indicate more or less ajipmximately tlie 

 relationship of genera possessing it. 



For the privilege of examining these genera I am indebted to 

 Mr. H. W. Bates. 



Tribe XX.— Psydrini. 

 Antennse moderate arising under a distinct frontal ridge, first joint moderately 

 stout, cylindrical, third longer than second, the three basal joints and the base of 

 fourth glabrous, 4 — 10 elongate-ovate, eleventh nearly as long as the two preceding. 

 Head triangular, moderately constricted behind the eyes forming a broad neck, 

 front with two supra-orbital setigeruus jnuictures the jtosterior distiiiil Iimjui ibe 

 margin of the eye, epistome slightly prolonged. Eyes oval, slightly liinicaie 

 behind, distant beneath from the buccal opening. Liibrum short, slightly cmiii- 

 ginate. Mandibles moderately prominent, arcuate, acute at tip, inner margin witli 

 a small tooth at middle, outer edge concave and without setigerous puncture. 

 Maxillse spinous within, the palpi moderate, the last joint longer than the pre- 

 ceding. Mentum broad, lateral lobes rounded, deei)ly emarginate and with a short, 

 broad, bifid tooth, the mental suture distinct. Ligula short and broad, truncate 

 and sexsetose at tip, the paraglossee semicorneous adherent in all their length and 

 not longer than the ligula, the palpi rather short, last two joints equal, the termi- 

 nal somewhat fusiform and truncate at tip. Thorax trapezoidal, sides with three 

 setigerous punctures, one at each angle and one slightly in front of middle. Body 

 not pedunculate, scutellum distinct between the elytra. Elytra slightly margined 

 at base near the humeri, sides narrowly inflexed, lateral margin slightly inter- 

 rupted posteriorly and with a short internal plica, disc punctato-striate, two dorsal 

 punctures on the third interval adjacent to the third stria, one-fourth from base 

 and one-fourth from apex. Prosternum not> prolonged. Mesosternum nearly fiat, 

 the middle coxse distant, epimera wide nearly equalling the episterna. Meta- 

 sternal epimera distinct, posterior coxse contiguous. Ventral segments 3 — 4—5 

 with posterior margins coriaceous. Legs moderate, the tibise snjooth externally, 

 the anterior emarginate within, the spurs distTant. 



The anterior tarsi do not difier in the sexes, the sexual characters are the same 

 as in Scarites. 



The only genus known to me which can be referred to this tribe is 

 Psyclrus. Its form is not unlike some Bembidia, the color piceous. 



Regretting the multiplication of tribes, I can find no place in which 

 the genus can be put and atn compelled to adopt the present course and 

 consider it the type of a tribe the affinities of which are in the direction of 

 NoTniux and Siagonu, as well as in a less marked degree toward Mario. 



Psydrus was originally placed near Ozsena, (Ann. Lye. iv, p. 153), 

 subsequently with Haplochile (== Nomius), as a group of the tribe 

 Broscini, a position retained in the Class. Col. N. Am. p. 30, Lacordaire 

 in the meantime placing it in the Morionini. None of these positions 



