SZ SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. Ill 



M. C. Lane, of Walla Walla, Wash., as L. triundulatus (Randall). 

 On the basis of larval characters it appears to be a distinct species 

 from the one that has been reared from Quebec, Ontario, Saskatche- 

 wan, and Alberta, the reared adults of which have been identified by 

 W. J. Brown as triundulatus (Randall). In a personal communication 

 Mr. Lane states, "I should probably have designated one of Brown's 

 species. It is the western variety, either L. nebraskensis (Bland) or 

 L. tigrinus (Fall)." The larva of L. tigrinus (Fall) is not known, 

 but tigrinus is a California species and thus less likely to be collected 

 in Washington. Therefore, this larva is believed to be nebraskensis 

 (Bland). 



Nothing is known of the habits of the larva. Structurally, it may be 

 distinguished from the larva of triundulatus by the following char- 

 acters of the ninth abdominal segment: Segment relatively broad 

 posteriorly and urogomphi more widely separated than in triundu- 

 latus; outer prongs of urogomphi (fig. i8, e) projecting dorsad, at 

 right angles to the inner prongs and almost at right angles to the 

 undivided parts of urogomphi; caudad notch more nearly V-shaped 

 than U-shaped ; and sharper "teeth" on lateral margins of dorsal plate. 



This larva measured 8 mm. in length and i mm. in width, at the 

 age of 6| months. Since the adults of nebraskensis are larger than 

 those of triundulatus it is expected that mature larvae should exceed 

 13 mm. in length. This specimen died and dried out before being 

 preserved and so it was not entirely adequate for a complete compara- 

 tive study. The specimen is deposited in the U. S. National Museum. 



THE LUDIUS FALLAX GROUP 



Figures 8, d; 19, 20 



KEY TO SPECIES 



From Europe 2 



From North America 4 



Dorsal plate of ninth abdominal segment with a transverse groove 



joining two longitudinal impressions ^ purpureus (Poda) (p. 93) 



Dorsal plate of ninth abdominal segment (fig. 20, o) without a trans- 

 verse groove 3 



Posterior part of frons bluntly pointed (fig. 19, b) ; usually 5 "sensory" 



appendices on second segment of antenna (fig. 19, d) 



tessellatus (Linnaeus) (p. 84) 



Posterior part of frons broadly rounded ; usually 2 "sensory" appendices 

 on second segment of antenna (fig. 19, e) . .castaneus (Linnaeus) (p. 89) 



Eastern North America medianus (Germar) (p. 92) 



Western North America S 



8 Information taken from Beling (1883, p. 264, "haematodes Fab."). 



