1 6 MEMOIRS ON THE COLEOPTERA 



B Similar in general characters but much narrower, more elongate, 

 less ventricose and less convex than in tularensis, opaculate 

 throughout; head smooth, with the feeblest traces of sculpture; 

 prothorax nearly, as long as wide, the sides evenly converging and 

 very evenly, moderately arcuate from apex to base, the latter 

 transverse and very feebly bisinuate; side margins very finely 

 reflexed and attaining the base; surface almost perfectly smooth 

 throughout, the anterior transverse impression feeble, the basal 

 rugulosity fine and shallow; elytra one-half longer than wide and 

 only a third wider than the prothorax, the punctures much smaller 

 and feebler than in either of the preceding, becoming obsolete 

 basally and stronger and close laterally and apically, the small 

 scattered fovese very distinct. Length (o 71 ) 16.5 mm.; width 5.8 



mm. California (Tulare Co.), Dietz opacellus n. subsp. 



Elytra wholly impunctate, the side margins of the prothorax very finely 

 reflexed and not attaining the base. Body stout, ventricose, convex; 

 head nearly smooth, the lobe of the labrum very strong, narrowly 

 truncate at tip; prothorax (9 ) a third wider than long, widest near 

 the apex, the sides thence rather strongly oblique and feebly arcuate 

 to the base, which is transverse and very feebly bisinuate; surface 

 nearly smooth, rugulose postero-laterally and at base, the anterior 

 transverse impression deep; elytra rather broad, oval, widest at the 

 middle, arcuately and acutely ogival apically in almost posterior 

 half; surface smooth, opaculate, with strong micro-reticulation and 

 fine subobsolete anastomosing creases, also with feeble traces of 

 very fine punctures apically; foveae very small, scarcely larger than 

 the asperate punctures bearing the setae. Length (9) 19.0 mm.; 

 width 6.8 mm. California (Mineral King Road, Tulare Co., 8000 

 feet), Fuchs laevis G. H. Horn 



This group presents a rather' more difficult taxonomic study 

 than any other and I have puzzled long over the most probable 

 inter-relationships of the various units. Horni is certainly a dis- 

 tinct species, but whether the forms from tularensis to lams con- 

 stitute a single species or not, I cannot quite make up my mind. 

 Opacellus is a very distinct form, but there is no record at hand 

 concerning the altitude of its habitat. 



In the above arrangement I have been obliged to omit xanti Lee. 

 and vandykei and fuchsi of W. Horn, not having seen any authentic 

 representatives of them. The descriptions of lecontei and inter - 

 medius are taken from the originals and with reference also to the 

 work of Mr. Leng. In the case of horni, its identity with collaris 

 is merely a surmise; the available material in this restricted section 

 is at present far too small for final judgment. 



