148 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. Ill 



are at least twice as long as the spiracles in the other abdominal seg- 

 ments and situated much farther caudad. Other important diagnostic 

 features are found in the nasale (fig. 28, c), which is tridentate at tip 

 with small median denticle, and in the mandible (fig. 28, b) with its 

 unusually robust distal half. The group is not closely aUied to any 

 other of the known Ludins larvae. 



Larvae of the pyrrhos group are yellowish brown, exceeding 20 mm, 

 in length when full-grown. Dorsum punctulate. Caudal notch small, 

 almost closed posteriorly, Urogomphi bifid, prongs subequal in 

 length; inner prong broad; outer prong less robust, terminating in 

 moderately blunt point. Dorsum of ninth abdominal segment (fig. 

 28, d) with 2 unpaired setae, and sometimes with faint short median 

 groove; anterior margin of dorsal plate well defined throughout; 

 3 rounded "teeth" {to), sometimes with pointed tips, on lateral mar- 

 gins of dorsum. On ninth abdominal segment the distance between the 

 pleural area and caudal notch equals one-quarter to one-third of 

 entire length of segment, exclusive of urogomphi. Frontoclypeal area 

 truncate posteriorly. One "sensory" appendix on second segment of 

 antenna. Second joint of maxillary palpus longer than first joint. 

 Eyes present, 2 prominent unpaired setae around each eye. Epicranial 

 plates each with 2 prominent unpaired lateroepicranial setae. Gula 

 short and very narrow. Presternum of prothorax of i piece, but 

 deeply incised on lateroposterior aspects, almost resulting in a separate 

 small median piece posteriorly. Without spinelike setae on episterna 

 of mesothorax and metathorax. Mediotergites of mesothorax and 

 metathorax with definite impressions. Mediotergites of abdominal 

 segments {mtg, fig. 28, a) with transverse branches of impressions 

 {trim) failing to reach middorsal suture and with a posterior trans- 

 verse row of 5 prominent setae arranged as 2 pairs with i unpaired 

 hair farther laterad. 



LUDIUS PYRRHOS (Herbst) 



Figures ii, e; 28 



Elater pyrrhos Herbst, Natursyst. Ins. Kafer, vol. 10, p. 30, 1806. 

 Corymbites pyrrhos (Herbst), LeConte, Trans. Amer. Philos. Soc, new ser., 



vol. 10, p. 447, 1853. 

 Ludius pyrrhos (Herbst), Van Dyke, Proc. California Acad. Sci., vol. 20, 



p. 394, 1932. 



The larval material of this species that was available for study was 

 not adequate for a description of greater detail than that given under 

 the pyrrhos group. 



