. 9. Nldivalvata marxii, dorsal view. 

 8. " " eyes of. 



10. " '• maxilla of. 

 13. " " side view. 



11. " angustata, nest of. 

 15. Ne%l o{ ifyrmekiaphila foliafa; dotted line at a represents bottom of place 



where stone lay. Space represented by dotted lines a and d, much fore- 

 shortened; b, where spider was caught; c, trap-door. 



" 16. 'Nest o{ Myrmekiaplula foliata in an ants nest; a a, laiuling in ants iiest, 

 leading off into galleries; b, entrance to ants nest; (/, lube of spider; r, 

 I rap-door. 



" 17. Nest of Nidwalvnta marxii, open. 



•' 18. " " " " closed. 



" 19. Palpal claw O, of P. corolinensis. 



'• 20. " '"9' " P- I'nrabivorus. 



"21. Palpal claw of P. 4-spinosus. 



"22. '* " 9»" M. foliata. 



"23. " " 9'" -^"- '>nci7-xii. 



Figs. I, 2, 6, g, 13 and 14, about natural size, 



ERE ATA. -In the first part of this article, pp. 109-117, for caribivorus where- 

 ever It occurs, read carabiiwus; for Notes, in title, read Nests; p. no, line 7, 

 note 1, for Canes, rea<l Cannes. 



Note on the secondary sexual characters of some 

 North American Coleoptera. 



By E. a. Schwarz. 



Hydrophilus ovatus. The two sexes differ not only in the structure 

 of the front tarsi but also in that of the maxillary palpi which, in the fe- 

 male, are slightly compressed, the three joints being about equal in 

 width. In the male, the palpi are much more compressed, especially 

 the second joint which is twice as wide as the last. 1 can hardly believe 

 that this obvious character should have been hitherto overlooked, still I 

 find no mention ofit in the liteiature at my command. It is not alluded 

 to by Dr. Horn (Can. Ent, XVII, 1885, p. 137-138). 



Myceioporus americanus TLVxd flavicollis. In addition to the sexual 

 characters mentioned by Dr. Horn (Trans. Am. Ent. Soc. VI, p. 123) 

 1 notice in the males of the above species a peculiar structure of the 

 seventh abdominal segment. This is broadly emarginate at apex and 

 its surface (so far as visible) covered with a dense filamentous vestiture 

 which is longitudinally striate, projecting in two lobes beyond the apex 

 of the segment. The lobes are divergent, narrowing toward the tip and 

 terminating in a fine seta. This structure is the same in the two species 

 which do not appear to differ except in coloration. 



