NORTH AMERICAN GEOTRUPINAE — HOWDEN 199 



This rare little species has been collected from May through June 

 only in the southern tip of Texas from Duval County southward to 

 Brownsville. Nothing is known of its habits. 



Bolbelastnus hornii (Rivers) 



Bradycmetus hornii Rivers, 1886, p. 61. Type, Sonora, Tuolumne County, Calif. 



(present location of type unknown). 

 Bolboceras hornii (Rivers) Schaeflfer, 1906, p. 253. 

 Bradycinetulus hornii (Rivers) Cockerell, 1906, p. 242. 

 Kolbeus hornii (Rivers) Chapin, 1946, p. 79. 

 Bolbelasmus hornii (Rivers) Cartwright, 1953, p. 100. 



I have examined specimens labeled "dug from burrow" and seen 

 others with "at light" labels. Presumably this rather common Cali- 

 fornia species has much the same burrowing habits as the species in 

 closely related genera. Of the 130 specimens examined, 6 were col- 

 lected in January, 6 in February, 7 in March, 38 in April, 61 in May, 

 and 7 in June. To my knowledge, the immature stages of hornii 

 have never been collected or described. 



Genus Eucanthus Westwood 



Eucanthus Westwood, 1848, p. 387; 1852, p. 26.— Schaeffer, 1906, p, 253 (as 

 Bolboceras in part). — Manee, 1908b, p. 459. — Blatchley, 1910, p. 937 (as 

 Bolboceras); 1928, p. 30.— Boucomont, 1911, p. 336.— Dawson, 1922, p. 

 195.— Cartwright, 1944, p. 30.— Ritcher, 1947, p. 10.— Robinson, 1948, p. 30. 



Genotype: Scarahaeus lazarus (=melihoeus) Fabricius, by mono- 

 type in Westwood (1848). 



Generic limitations: Given by Westwood (1848, p. 387) : "Corpus 

 minus depressum quam in reliquis; pronoto antice baud retuso. 

 Tibiae anticae dentibus duobus apicalibus magnis aliisque minutus 

 externus versus basin armato. Elytra punctato-striata; singulo striis 

 5 tan turn inter humeros et suturam, punctis, profundis." 



Other useful characteristics are: Coarse lateral punctures of prono- 

 tum with about half of their rims elevated, giving tuberculate appear- 

 ance; transverse hornlike carinae, one on clypeus, one on vertex, 

 present in both sexes; humeral angle of elytron not broadly rounded, 

 usually with tubercle. 



Male genitalia: Both the genitalia and genital capsule are rather 

 simple and poorly sclerotized with no usable characters noted. How- 

 ever, careful study of the genitalia may be helpful in some cases for 

 setting specific limits. 



In the genus sexual and size variation is very pronounced. In 

 both sexes the size of horns (carinae) and tubercles may vary, and 

 this size to some extent appears coupled with body size and degree 

 of coarse punctation. 



327015—55 4 



