NORTH AMERICAN GEOTRUPINAE — HOWDEN 169 



filled with very finely divided, black surface humus and sand. The 

 burrow was no longer vertical, having veered to one side at an angle 

 of approximately 40 degrees. Also, the subsoil had suddenly become 

 considerably damper. The portion of the burrow packed with the 

 black humus was slightly over 3 inches long, going to a depth of 22 

 inches. In its shghtly tapered lower end was a fully grown third-stage 

 larva. The larva appeared to be in an oval pupal cell, 17 by 10 mm. 

 at its widest point, and within one-half inch of the lower end of the 

 burrow. The position of the pupal cell can be noted in the diagram 

 (pi. 10, fig. 3). Plate 13, figure 2, shows the larva as it was found in 

 the burrow. Most of the black humus in the burrow, about 60 mm. 

 of it, had been in large part consumed, being replaced by very small, 

 scattered, dry, black fecal pellets. The food cell (pi. 13, fig. 2), even 

 though largely consumed, had the same general appearance as the un- 

 consumed humus noted in the burrow dug on Sept. 4, 1951. The 

 larva was immediately preserved and is subsequently described. It 

 is evident that the larva of farctum, as in other Geotrupinae, has a 

 rapid development. The burrow was made between Sept. 4-11, 

 1951, and the full grown larva was found on October 31 ; this indicates 

 a maximum period of development of slightly under two months. 



On the same date, Oct. 31, two other fresh burrows were discovered. 

 The first burrow, largely concealed by a covering of dead oak leaves, 

 was in a rather shaded spot. The burrow yielded a single, newly 

 emerged female at a depth of 14 inches. The excavation of the second 

 burrow produced a slightly teneral male at a depth of 1 1 inches. Both 

 specimens, apparently newly transformed, were making fresh burrows, 

 but no evidence of any old burrows could be found. 



Further careful search of the area and subsequent visits in 1951 and 

 1952 did not yield further specimens. 



The following description of the larva of Bolbocerosoma farctum 

 is based on one third-stage larva collected Oct. 31, 1951, at Faison, 

 N. C, by H. Howden and P. O. Ritcher, from a burrow previously 

 marked. 



The larva differs from Ritcher's (1947, pp. 11, 12) description of 

 Bolbocerosoma in the following respects: Maximum width of head 

 capsule 3.4 mm. Antennae (pi. 6, fig. 2) and head capsule almost iden- 

 tical except for an additional exterior frontal seta on one side (making 

 the number 2 or 3), and 4 to 6 anterior frontal setae. Labrum entire, 

 truncate (pi. 6, fig. 4), width 2% times greater than length. Man- 

 dibles, maxillae, hypopharynx, and glossa not varying in any particu- 

 lar from Ritcher's description. Tormae of epipharynx (pi. 6, fig. 4) 

 not united mesally, each with a pternotorma, on the inside of which 

 are found 3 to 5 sensilla. Otherwise epipharjmx is similar. 



