DESCRIPTIONS OF NEW SPECIES. 15 



Harris as A. agricola; what I consider as Say's species has the 

 hind angles of the thorax obtuse but not rounded. The present 

 species is readily known among those with rounded angles by the 

 more strongly depressed and punctured sides of the thorax. The 

 elytra are distinctly sinuate near the tip, aud the terminal spur of 

 the front tibiae is slightly dilated.* 



4S. A. radis. Elongatus, nigro-piceus nitidus subaenescens, parce 

 breviter pubescens, capite utrinque punctato, thorace subcordato, lati- 

 tudine vix breviore, lateribus late rotundatis postice subsinuatis, an- 

 gulis posticis rectis, antice et postice grosse punctato, ad basin utrinque 

 impresso, elytris interstitiis 2ndo 4to et 6to fortiter subbiseriatirn punc- 

 tatis, externis duabus disperse punctatis, lmo et 3io punctis pluribus 

 prope strias sitis, autennis nigro-piceis, basi rufescentibus; Long. '40. 



California, one male. Of the same size and shape as A, alter, 

 nans, but differs by the much coarser punctures ; as in the other 

 species of this section, having the alternate intervals of the elytra 

 punctured, the elytra are strongly sinuate near the tip, but in the 

 present species the sutural angle is not rounded. The terminal 

 spur of the front tibia? is dilated each side into a very distinct 

 tooth, almost as in the first and second sectious of the genus. 



* Tbe black species of Anisodactylus inhabiting the eastern slope of 

 our territory, and belonging to the present section of tbe genus, may be 

 readily distinguished by the following table ; in all of them tbe terminal 

 spur of the front tibia? is but slightly dilated each side. 



A. Hind angles of thorax obtuse and rounded ; 



Sides of thorax scarcely depressed behind ; 



Base of thorax scarcely impressed or punctured. 1. SIGEEHIMUS. 



Base of thorax punctulate and impressed. 2. punctulatps. 



Sides of thorax distinctly depressed and together with tbe base punc- 

 tured ; 



Elytra opaque, not sinuate towards the tip. 3. fcrvcs. 



Elytra not opaque, distinctly sinuate near the tip. 4. harrisii. 



B. Hind angles of thorax obtuse, not at all rounded ; 



Thorax wider and less convex, with the sides more widely depressed. 



5. MELAXOPUS. 



Thorax more convex, less transverse with the depressed margin nar- 

 rower ; 

 Hind angles of thorax quite obtuse. 6. RIGRITA. 



Hind angles of thorax nearly rectangular. 7. agrio>la. 



