186 DESCRIPTIONS OF AND OBSERVATIONS ON 



EUCNEMIS, Mrens ? Mannerhciw. 



t Pectus not injleeted at the edge, nor canaliculate beneath, to receive 



the antennsR. 



* Tarsi simple. 



1. E. miiscidiis, S. {Elater muscidus, Ann. Lye. N. Y., I., p. 256.). 

 The largest knovvn species of the United States. 



2. E. unicolor, S. (Elater unicolor, Ann. Ljc. N. Y., I., p. 255.). 

 Also a large species. 



3. E. heterocerus. Light brown, sericeous ; three last joints of the 

 antennoe largest. — Inhab. Indiana. 



Body light reddish brown, sericeous, with bright yellow hair; punc- 

 tures minute, universal : antennx, first joint as long as the three next 

 together; second joint smallest: third nearly as long as the two next; 

 fourth, fifth, sixth, seventh and eighth short, equal; remaining joints 

 each nearly as long as three of the preceding ones together, and some- 

 what dilated : thorax with an indented line at base; spines prominent, 

 acute : scutel rounded behind : elytra with impunctured striae : pectus 

 on the lateral margin slightly concave. — Length half an inch. 



The singular form of the antennae will distinguish this fine species 

 from any other yet known. It will form a separate genus- 



4. E. quadricollis. Head and thorax with large crowded punctures ; 

 posterior thoracic angles nearly rectangular. — Inhab. Indiana. 



Body piceous black, with yellowish hairs; head with crowded, large 

 punctures, longitudinally confluent on the vertex: antennse rather dis- 

 tant at base, not seated in approximated sinuses, but under frontal ele- 

 vations; second joint more robust than the third, and equally long; 

 fourth joint rather longer than the third ; remaining joints obconic, 

 subequal, the last a little longer: palpi, terminal joint oval: thorax 

 transverse quadrate, with punctures like those of the head, but not 

 much confluent; anterior angles rounded ; lateral edges nearly parallel, 

 very slightly contracted towards the posterior angles, which are nearly 

 rectangular, a little acute, not continued backward beyond the line of 

 the base: elytra with punctured striae and minutely punctured inter- 

 stitial lines: pectus with less crowded punctures than the thorax: 



