158 MEMOIRS ON THE COLEOPTERA 



during the past ten years, but its source is unrecorded. The species 

 may be distinguished easily from brunneus by its narrower, more 

 rhomboidal form, longer prothorax, with more rectilinear sides, 

 more acuminate elytra, more minute sculpture and several other 

 characters. 



I have not seen the Ischyrus extricatus of Crotch, and so cannot 

 pass any opinion upon it, further than to say that it also is more 

 likely to be a Pseudischyrus than an Ischyrus. 



Mycotretus Chev. 



This is a tropical genus and the Triplax sanguinipennis and Tri- 

 toma pulchra of Say, assigned thereto by Crotch, do not belong to it 

 but are normal species of Tritoma, where their bodily facies would 

 place them at first sight. There is considerable variety in the form 

 of the men turn in Tritoma, and in biguttata it appears quite different 

 from that of unicolor; in the latter it does not differ essentially from 

 that of sanguinipennis, and the elytral striation toward the suture 

 and scutellum is exactly the same in the latter species and unicolor, 

 except in degree of development. The antennae are alike in both, 

 but in a Mexican species of true Mycotretus at hand, which the work 

 of the author impels me to identify as rubidus Gorh., the mentum 

 does not differ essentially; the long, loose and compressed 4- 

 jointed antennal club is however of an entirely different order from 

 that of any of the species named above. The following seems to 

 be an undescribed species of Mycotretus: 



*Mycotretus nubifer n. sp. Evenly elongate-elliptic, strongly convex, 

 shining, pale brownish-flavate in color throughout the body, legs and 

 first seven antennal joints, the antennal club, the first joint of which is 

 rather small, a nubilous spot on the occiput, six clearly defined spots 

 on the pronotum, two rounded and widely separated near the base of 

 each elytron, the inner of which is faint and nubilous, a sharply marked 

 broad fascia at the middle, not reaching the sides and prolonged in a cusp 

 on the suture half way to the scutellum and the elytral suture behind the 

 fascia to the apex, very narrowly, black; on each elytron near the apex 

 there is also a transverse discal area of such faintly nubilous character 

 as to be barely noticeable; head fully half as wide as the prothorax, very 

 finely, loosely punctate; antennae longer than the prothorax, which is 

 four-fifths wider than long, the sides moderately converging, very evenly 

 and moderately arcuate from base to apex; surface minutely, evenly and 

 not closely punctulate, the base unmargined, having a gradually formed 

 and rather broad median lobe, the edge at the sinuses having the punc- 

 tures just visibly less minute; besides the six rounded and sharply defined 



