l88 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. Ill 



believed to be E. costalis v^as described from Finland by Prof. 

 U. Saalas (1937, pp. 68-72, "Probably Orithales serraticornis Payk." ; 

 1938, pp. 53-55), who kindly loaned the writer material for exami- 

 nation. 



These two species are very similar in structure and are most readily 

 separated on the basis of geographic distribution. However, Brown 

 (1930, p. 162) has indicated that they represent only one of the 

 two distinct species groups included in the genus. On the basis of 

 the larvae examined, Eanus is an isolated genus, readily distinguished 

 by the following characters : Dorsum of ninth abdominal segment 

 (fig. 40, d, e) strongly convex, and without raised lateral margins; 

 urogomphus (iir) undivided, blunt, and with a strongly sclerotized 

 bar on inner aspect ; abdominal pleurites absent or practically so 

 (fig. 40, b, c) ; abdominal mediotergites {mtg, fig. 40, b) with very 

 faint, short impressions, and with only 3 prominent unpaired setae in 

 the posterior transverse row, 



Eanus larvae are pale yellow ; up to 18 mm. in length ; with in- 

 conspicuous sculpture. Ninth abdominal segment with small caudal 

 notch, and distance between pleural area and caudal notch about one- 

 fifth length of segment, exclusive of urogomphi. Nasale of i sharp 

 tooth. Eyes present; bordered by 2 unpaired setae. Two unpaired 

 later oepicranial setae on each gena. Gula extremely narrow, area 

 practically closed posteriorly. One "sensory" appendix on second 

 segment of antenna. Mandible (fig. 40, a) very robust with toothlike 

 expansion of dorsal margin of inner face of distal half. Presternum 

 of prothorax divided, the posterior median piece being very small. 

 Mesothorax and metathorax with faint but definite impressions on 

 mediotergites, and without spinelike setae on episterna. 



Material used in study of the genus. — E. decoratus (Mannerheim) : 

 Eleven examples were examined, including the exuviae of three 

 reared specimens. All were from the province of Quebec and the 

 reared adults were identified by W. J. Brown, of Ottawa. (C.N.C.) 

 Material identified through rearing is listed below : 



i; Mount Lyell, Gaspe County, Quebec, 1,500 ft.; (no date); adult found 



emerged on Oct. i, 1934; C. C. Smith. (C.N.C.) 

 2; Cascapedia River, Quebec; adults emerged Sept. 7 and Sept. 20, 19351 M. L. 



Prebble. (C.N.C.) 



E. costalis (Paykull) ( ?) : One larva from Suomussalmi, Finland, 

 was all the material available for examination. This was an unidenti- 

 fied specimen that is believed to be E, costalis because of its morpho- 



