CICINDELIDAE. 3 



nre eight in the male and seven in the female, the seventh in the 

 latter sex being elongated so as to conceal the eighth. 



This family is divided by Lacordaire into five tribes, of which 

 but three are found within the limits of the United States, and are 

 distinguished in the following manner: — 



A. Third joint of maxillary palpi longer than the fourth. 



First joint of labial palpi very short. Manticorini. 



First joint of labial palpi elongated. Megacephalini. 



B. Third joint of maxillary palpi shorter than the fourth. Cicindelini. 



Tribe I.— MANTICORINI. 



The species of this tribe are apterous, with the elytra connate; 

 the eyes are small, and in this respect they differ from all other 

 members of the family; the first joint of the labial palpi is very 

 short, and hardly extends beyond the emargination of the mentum. 



These insects are probably crepuscular or nocturnal in their 

 habits. I am informed by Dr. Wm. A. Hammond, that speci- 

 mens of Amblychila were found by him running about in the early 

 morning of cloudy days. The only specimens of Omus found 

 by me were drowned in a rain-pool near San Francisco. In 

 Amblychila the usual differences between the sexes fail ; the tarsi 

 of the male are not dilated, and the abdomen has only six ventral 

 segments. In Omus the anterior tarsi of the male are widely 

 dilated, and the Tth ventral segment is distinct. 



Two genera of this tribe are found in our country, and both are 

 peculiar to it. Amblychila, having wide epipleurae, occurs in 

 Kansas, New Mexico, and probably in California. (1 species.) 



Omus, having narrow epipleurse, is found in California, Oregon, 

 and Washington Territory. (3 species.) 



Tribe II.— MEGACEPHALINI. 



The native species of this tribe are but two in number, and 

 belong to the genus Tetracha. T. virginica is crepuscular in its 

 habits; T. Carolina extends from the Atlantic to the Pacific coast. 



Tribe III.— CICINDELINI. 



Of this tribe the species are very numerous. Those of our 

 fauna belong, with one exception, to Cicindela, and many of them 

 are seen on roads exposed to the sun, flying actively on the least 

 alarm, and again alighting at the distance of a few paces. The 



