NORTH OF MEXICO. 



317 



The second section of the sub-genus contains those species in which the thorax is 

 strongly constricted at base, almost pedunculate, and the lateral marginal line not attain- 

 ing the basal margin. On account of the extreme variation of which the species are sus- 

 ceptible, many more names have been applied to the varieties than we can draw lines to 

 separate. On account of the difficulty of ascertaining accurately the forms to which Esch- 

 scholtz's names were applicable, Dr. Leconte obtained types from Europe, some of which 

 were carefully compared by the late Dr. Schaum, while others were furnished by Mene- 

 tries and Motscbulsky from the original collection of Eschscholtz, and with this assistance 

 and the large numbers of specimens in Dr. Leconte's cabinet and my own, I can safely as- 

 sert that but three species should be recognized in the fourteen varieties already known to us. 



E. parvioollis, Esch., Zool. Atl. 8, p. 12; Mann. Beitrag. 271; plunnla, Esch., et Mann. loc. oit. ; producta, 

 Mann., loo. oit.j parsieollis, Esch., et Mann. loo. oit.; saabrota, Esch., et Mann., loo. oit.; comtriota, Leo., Px'oc. 

 A. sad. 1858, p. 187. 



This species has the thorax comparatively smooth. The punctures, though rather 

 coarse, arc never confluent, and the thorax has never the scabrous appearance of the two 

 succeeding species. The elytra are also rather coarsely punctured than intricately rugose, 

 as in the next. The form of elytra varies greatly, and on this alone have been founded 

 the numerous names cited above as synonyms. 



E. producta has the humeral angles very distinct and the disc of the elytra more flat- 

 tened, approaching in this respect planipennis. The humeral angles, however, become 

 less distinct, and at the same time the disc more convex, and the transition is very grad- 

 ual and easy through planata and parvicollis to scabrosa. Typical specimens of all the 

 species are before me, and it is easy to complete series leading gradually from one form to 

 the other, all preserving, however, the common characters given in the synoptic table. 



This species is abundant at San Francisco and around the bay in a southerly direction. 



Length .42-.G4 inch. 



E. oordata, Esch., Zool. Atl. ?>, p, 12; Mann. Beitr., p. 27H; tubereulata, Esch., ct. Mann. loc. oit.; iiilncata, 

 Mann., Beitr., p. 275!; rolundipennis, Leo., striata, Leo., Pacif. R. It. Reports, App. 1, p. 50. 



.Differs from the preceding in having the thorax densely and confluently punctured. 

 The sidc-s of the thorax are more strongly rounded in front, behind the middle nar- 

 rowing rather suddenly, causing them to appear somewhat sub-angulate. This character is 

 seen an the next species, but never in the previous one. The elytra are also more rugose, 

 the spaces between the punctures arc- elevated and convex, and more or less confluent 

 transversely. 



The species is abundant in the region of San Francisco, extending its range to the 

 southward through the Sacramento Valley and into Oregon, where it is replaced by the 

 next species. 



Length .40— .(52 inch. 



AMERI. 1TIILOSO. SOC VOL. XIV. — 80 



