THE CANADIAN ENTOMOLOGIST 303 



First dorsal plate in type 1.64 times wider than long. Eleventh 

 and thirteenth plates, but especially the latter, with posterior 

 angles very slightly produced as usual. 



Coxal pores mostly 2, 3, 3, 2; 2, 3, 3, 3 or 3, 3, 3, 3. 



Spines of the anal legs, o',','"'" , claws 2; of the penult, ',',',[ ,. 



, -. ,- . i  , , o,o,2,i,o r ,1 ii-i 0,0,2,1,1 0.0,2, T.I 



claws 2; of the thirteenth, ^7—; of the twelfth, OOOIt , or 



0,0.1,1,1 



0.0,0,2,1 c . ,, . . rr 1 O.O,0.I,I 



of the sixth to eleventh, o ' ',^, ; of the third to fifth, 0i ' o ; o> iJ7; of the 



, 0,0,0,0. 1 . , (. 0,0,0,0,0 

 second^-^;-: of the first, , , , , - 



Claw of the female gonopods of the usual tripartite form, the 

 teeth acute, the median longest and the lateral subequal. Basal 

 spines decidedly broader than usual, much as in Tidabius, those 

 of each pair close together; moderately long. Outer spine longer 

 and broader than the inner; its sides subparallel from base to 

 apical division, which is short and acute, or weakly incurved at 

 middle; edge of apical portion usually finely crenulate. Inner 

 spine of similar shape to that of the outer or with sides sometimes 

 converging from base to apical portion. 



Length 7 — 10 mm. 



This species is very distinct from any previously known. It 

 is aberrant in a number of features, such as the large single ocellus 

 and the broad basal spines of the female gonopods. It is the 

 largest known species, and the one farthest from what seems to be 

 the centre of distribution for the genus. The process on the 

 penult legs of the male is much like that of virginiensis; but 

 michiganensis differs clearly from that species in its much greater 

 length, which is about twice that of virginiensis, in the spining of 

 the legs, and in the form of the basal spines of the female gonopods. 

 N. fungifuopes, the species that has been taken geographically 

 nearest to it (Western New York), is readily separable from it r 

 as from all others now known, in lacking dorsal spines on the 

 posterior legs; also the form of the process on the penult legs of 

 the male is distinctly different. 



Many specimens of this species were taken. 



Class DIPLOPODA. 



7. Polyzonium rosalbum (Cope). 

 One specimen. 



