168 MEMOIRS ON THE COLEOPTERA 



larly simple and perforate, impressed along the middle from the base 

 to the fourth segment, this impression not being visible in tantilla; 

 legs and antennae very much longer than in tantilla. Length (cf) 

 10.5 mm.; width 3.8 mm. Lower California (Santa Rosa), Beyer. 



exilis n. sp. 



Form and facies somewhat as in opaca but with the elytra more narrowed 

 at base and expanded posteriorly, dull, black; elytra with three 

 vittce of minute granules, each bearing a minute spine-like hair; 

 head moderately coarsely, not densely punctured; prothorax broader 

 than long, slightly narrower in front, the sides feebly arcuate, with a 

 slight sinuation posteriorly, the hind angles acute; surface moderately 

 convex, with faint trace of a median groove, coarsely and closely 

 punctured, more densely at the sides; elytra broadest behind the 

 middle, the humeri distinct but not rectangular, the marginal ridge 

 nearly reaching the apex; surface feebly convex transversely, with 

 three vittse one close to the suture, formed of minute granules, 

 each with a minute hair, a few scattered granules in the interspace 

 next the margin, otherwise quite smooth; prothorax beneath punc- 

 tate medially, granular at the sides; meso- and sides of the meta- 

 sternum coarsely granular; abdomen moderately finely, not closely 

 punctate, bearing short hairs; legs roughly punctured. Length 18.0- 

 21. o mm. Lower California (Pescadero, west side). [Asida sub- 

 vittata Horn] subvittata Horn 



I am quite at a loss to know where to place the Asida subvittata 

 of Horn, its opaca-Yike facies, with elytra enlarged posteriorly, 

 feebly punctured abdomen and absence of discal lateral costa on 

 the elytra being incompatible with Heterasida proper; but, at the 

 same time, there are some characters which seem to indicate that 

 it may be more fittingly attached to Heterasida, provisionally, than 

 to any other genus here denned; among these may be mentioned 

 the feebly impressed median line of the pronotum, a rather unusual 

 character and the aggregation of the elytral punctures, which are 

 here granuliform, into clearly denned vittse, which is one of the 

 notable features of Heterasida bifurca and unknown elsewhere 

 among American species. I have but little doubt, however, that 

 subvittata really constitutes the type of a distinct generic group 

 peculiar to Lower California. 



There are so many important differences between the bifurca 

 type and connivens, tantilla and exilis, affecting the entire habitus, 

 sculpture and form of the basal angles of the prothorax, that it is 

 difficult to understand why Dr. Horn should have even suspected 



