AMERICAN COLEOPTERA. 283 



entire extent. The dark spaces at the apex and base of the thorax are 

 present in all the specimens before me, and are always wanting in the 

 other two species. 



Occurs in Arizona. 



The three species above cited form a conspicuously defined little group, 

 characterized by their black elytra maculate with clear yellow. The 

 essential characters of each are as follows : 



Oval, slightly oblong, thorax entirely immaculate. Elytral spots conspicuous, 

 more or less confluent in fasciae; epipleurae piceous insignis. 



Oval, rather broad, thorax with a narrow ante-scutellar piceous space. Elytral 

 spots small, not confluent; epipleurae piceous pictus. 



Oval, rather broad, thorax with bilobed apical and basal spots. Elytra with few 



yellow spots; epipleurae pale lateralis. 



L. insignis Slip., occurs in Texas, pictus Cast., in Arizona and Lower 



California, lateralis Horn, in Arizona. 



HYDROPORUS Clairv. 



H. palliatus n. sp. — Oval, moderately convex, without pubescence, surface 

 shining, color piceous; legs, palpi, antennae, epipleurae and base of elytra pale 

 yellow. Head with scarcely any trace of punctuation. Thorax with sides very 

 feebly arcuate, the margin very narrowly thickened, surface punctured, rather 

 closely along the base and sides, quite densely near the hind angles, a subapieal 

 series of coarser punctures. Elytra paler than the thorax, the basal pale band of 

 varying width extending from the humeri to the suture ; surface sparsely and 

 rather finely punctured, and with two indistinct series on each elytra of coarser 

 punctures. Prosternal process moderate. Articular lobes of hind coxae truncate, 

 the outer angles acute, the cotyloid cavities distinctly separated. Sides of hind 

 coxae, epipleurae and abdomen coarsely punctured, abdomen at middle more 

 finely and less densely punctured. Coxal lines deep, nearly parallel, slightly 

 divergent only in front. Third joint of anterior and middle tarsi deeply bilobed. 

 Length .14 inch ; 3.5 millim. 



I have examined about a dozen specimens and find no special sexual 

 differences. I refer this species to Dr. Sharp's Group 8, in association 

 with vi/is and others. The shining surface and pale band at the base of 

 the elytra make it a very conspicuous species. 



Occurs at Crystal Springs, California. 



H. picturatus n. sp. — Broadly oval, form of rivalix. Beneath piceous, ab- 

 domen at times rufescent at base and apex. Head yellow, a little darker pos- 

 teriorly, surface very sparsely and finely punctured. Thorax with regularly 

 arcuate sides, the side margin not thickened, hind angles obtuse, surface with an 

 extremely fine punctuation, with coarser punctures in the basal and subapieal 

 regions, lateral impressions vague, color yellow with broad basal and apical spaces 

 piceous, so that but a narrow line of yellow divides them. Elytra finelv and 

 densely punctured, with very coarse punctures irregularly placed and with feeble 

 traces of two dorsal striae, color yellow with interrupted black suture transversely 

 confluent, forming a conspicuous oval spot near the middle of the vittae, another 

 posteriorly and a very irregular space extending to the side margin. Presternum 



