pO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. Ill 



but the largest specimen available for use in the present study mea- 

 sured only 12.5 mm. 



It is possible that castaneus belongs to a distinct but closely re- 

 lated "species group," since in the characters of frons, gula, and 

 antennae it departs from the general pattern found in tessellatus, 

 viduus, homhycinus, and medianus. 



Material used in study. — Three examples were examined, including 

 the last larval exuvium of a reared specimen the adult of which was 

 made available to the writer. Neither of the two whole larvae was 

 collected at the same time as the reared specimen, but all three were 

 from Denmark. The larvae examined are deposited in the U. S. 

 National Museum. Notes on the reared specimen follow: 



i; Holte, Denmark; Sept. i, 1895; A. Ditlevsen. (R.V.A.C.) 



LUDIUS VIDUUS Brown (?) 



Ludius viduus Brown, Canadian Ent., vol. 68, p. 103, 1936. 



Brown (1936b, pp. 103-104) shows this species to be widely dis- 

 tributed over the southern part of British Columbia where it has 

 been found together with bombycinus (Germar). The larva described 

 below was collected under a stone on a hillside bearing conifers. 



The larva of viduus differs from that of tessellatus (Linnaeus) 

 in being of paler color, especially on first to sixth abdominal segments, 

 in possessing more setae on thorax and abdomen and more spinelike 

 setae on the legs, and in having the inner prongs of urogomphi twice 

 as long as the outer prongs. It is much more closely related to bom- 

 bycinus (Germar), from which it differs in antennal characters. 



Length 17 mm.; greatest breadth 3.0 mm., on fourth and fifth ab- 

 dominal segments. Only one specimen was available for examination 

 and its relative maturity is unknown. 



Dorsum transversely banded with chestnut brown and paler brown, 

 anterior part of each segment darker; first to sixth abdominal seg- 

 ments palest. 



Antenna with second segment slightly more than one-half as wide 

 as long and bearing 6 conical "sensory" appendices just ventrad to 

 base of third segment. 



Each tergite of prothorax with an irregular anterior transverse 

 row of 20 to 25 setae, a posterior transverse row of 10 to 14 setae, 

 and 2 setae along lateral margin. Each mediotergite of mesothorax 

 and metathorax with posterior transverse row of 12 or 13 setae and 

 6 to 8 setae near lateral margin. Each mediotergite on first to eighth 

 abdominal segments with irregular posterior transverse row of 15 to 



