l80 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. Ill 



Only large and moderate-sized species are known, the mature larvae 

 usually exceeding 20 mm. in length. Dorsum of ninth abdominal seg- 

 ment (fig. 37, c) with median dorsal groove (mg), without setae on 

 the central area, frequently with noticeable pits, and with 3 or 4 

 prominent "teeth" (to) on each lateral margin. Nasale tridentate at 

 tip. Subnasale of many fine teeth. Two unpaired lateroepicranial 

 setae on each gena. Gula short and narrow. One "sensory" appendix 

 on second segment of antenna. Mandible (fig. 37, a) usually with 

 relatively short retinaculum (ret). Presternum of prothorax undi- 

 vided. Mesothorax and metathorax with distinct impressions on 

 mediotergites, and up to 8 spinelike setae on each episternum. Each 

 abdominal mediotergite with 5 or more prominent, unpaired setae in 

 posterior row. 



PROVISIONAL KEY TO SPECIES OF HEMICREPIDIUS 



1 . From Europe 2 



From North America 3 



2. Distance between caudal notch and pleural area of ninth abdominal seg- 



ment about one-seventh total length of segment, exclusive of uro- 



gomphi ; frontoclypeal area almost pointed posteriorly 



Athous hirtus ( Herbst) ( ? ) 



Distance between caudal notch and pleural area about one-fifth length of 



segment ; frontoclypeal area truncate posteriorly 



Athous niger (Linnaeus) 



3. Inhabiting rotten wood ; collected at Lethbridge, Alberta 



Hemicrepidius sp., near carbonatus (LeConte) 



Inhabiting soil, rarely in forest litter 4 



4. Basal segment of labial palpus with small seta ventrally ; western North 



America (larvae from Walla Walla, Wash.) 



H, carbonatus (LeConte) 



Basal segment of labial palpus without seta ; east of Rocky Mountains . . . 



H. memnonius (Herbst) 

 H. hemipodus (Say) 

 H. bilobatus (Say) 



Material used in study of the genus. — Reared adults of the follow- 

 ing species of Hemicrepidius have been identified by W. J. Brown, 

 of Ottawa: memnonius (Herbst), hemipodus (Say), bilobatus 

 (Say), and "Hemicrepidius sp., near carbonatus (LeConte)." Reared 

 material was also available of Athous niger (Linnaeus). 



H. memnonius (Herbst) : The larval exuviae of 3 reared speci- 

 mens were examined, but no reliably named whole larvae were 

 available. 



2; Fredericton, New Brunswick; (no date); both reared; R. P. Gorham. 



(C.N.C.) 

 i; Cornwallis, Pa.; April 1927; reared; C. A. Thomas. (Pa.C.) 



