NO. 2134. NORTH AMERICAN COLLEMBOLOVS INSECTS— FOL^OM. 481 



Tenent hair single, knobbod, unusually long, about one and one-half 

 times as long as the unguis, Dentes gradually tapering. Mucrones 

 two-sevenths as long as dentes, minutely tuberculate, in form as in 

 figures 11 and 12. Anal spines (fig. 13) two, half as long as hind 

 migues, curving, on prominent contiguous papillae, which are shorter 

 than the spines. Clothing mostly of short curving setae, as in figure 

 14. Length, 1.6 mm. in specimens studied by me; 2.25 mm. accord- 

 ing to Guthrie. 



The present description and figures are from 13 cotypes (slide No, 

 53a, Univ. of Minn.), collected by Guthrie, May 2, 1899, in Minnesota. 



This species is not the European A. schneideri Schaffer, as I have 

 learned by comparing it with seven specimens of the latter sent to 

 me by Doctor SchafFer. In scJmcidcri (synonymous with sahlhrrgi 

 Reuter) the anal spines are straight and not longer than the papillae, 

 and the mucrones and unguiculi are different in form from those of 

 this species. 



Guthrie found tliis form to be abundant in moist situations, as 

 under boards and in crevices in a living tree where the sap was 

 exuding. 



The cotypes are in the collection of the University of Minnesota. 



ACHORUTES MATURUS, new species. 

 Plate 8, figs. 15-21. 

 Achorutes schottili'EvrEn, Guthrie, 1903. 



Dark blue, grayish blue, or grayish, with round or oval spots made 

 by hypodermal nuclei. Eyes eight on each side. Postantennal 

 organs (fig. 15) \\dth four peripheral tubercles and a large oval 

 "Nebenhocker." Antennae shorter than the head, with segments as 

 11 : 14: 17: 26, in relative lengths. Sense-organ of third antennal seg- 

 ment as in figure 16. Body stout. Unguis (fig. 17) stout, unidentate 

 beyond the middle of the inner margin. Unguiculus about half as 

 long as unguis, lanceolate, acuminate. One long knobbed tenent 

 hair, often extending as far as the apex of the unguis. Dentes stout, 

 slightly tapering, not swollen apically and without large dorsal 

 tubercles. Mucro (figs. 18, 19) two-fifths dens in length, elongate- 

 triangular, with outer lamella terminating before the apex, which is 

 rounded and upturned. Anal spines (fig. 20) two, slightly curving, 

 small, less than one-third the hind ungues in length. Clothing (fig, 

 21) sparse, of short stiff setae. Length, 1 mm. 



This species resembles the European manuhrialis Tullberg (schdtti 

 Reuter), for which Guthrie mistook it. I have compared two of 

 Guthrie's specimens with four of manuhrialis, which I received from 

 Doctor Schaffer, and find that maturus differs in having no coarse 

 dorsal tubercles on the dentes, in having relatively longer dentes, 

 curving anal spines, and another type of clothing. 

 10600°— Proc.N.M.vol.50— 16 31 



