1887.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 320 



leacliiug- beyond the body. Segments not more than 4G. Scuta thickly 

 marked with small longitudinal depressions (under a half-inch glass). 

 Spiracles two to each segment in one line on either side of the body. 

 In some specimens the subsegraeuts are some of them furnished with 

 spiracles so that scuta may have four spiracles, but never in more than 

 two rows. The scuta decrease in width very rai)idly cephalad and 

 caudad; the first scuta is one-half and the last one-tenth the width of 

 the body. 



Length, IS-""' ; width, 3™"^. 



Twenty specimens are in the collection, all from Bloomington Town- 

 ship, Monroe County, Indiana. 



2. Polydesnius castaneus, spec. uov. Plate xii. 



Dark chestnut to olive-gray with a very indistinct black mesodorsal 

 line and pinkish lateral laminj©. Vertex chestnut or concolorous with 

 the body ; vertex furrow strongly pronounced and in the dark variety 

 piceous; cephalic margin of the labrum broadly and deeply emarginate 

 and thickly fringed with hairs; four long sette are arranged in a curved 

 line half way between the cephalic margin of the labrum and the bases 

 of the antennae. Antennte much less approximate than in P. erythropy- 

 gus, pilose and concolorous with the body, a ring of lighter color distad 

 of each joint ; basal joints yellowish white, each bearing one or two long- 

 setce. First scutum nearly semicircular. Anal scutum triangular, very 

 acute behind, with ten long hairs on the anal valves, two-thirds to three- 

 fourths the length of anal scutum. Feet pilose, dirty white and concol- 

 orous with the ventral side of the body. The genital appendages of the 

 male are of the P. erythropygus type, but very diiierent in detail. They 

 are composed of two smooth subconical tumuli, to which are articulated 

 two long curved spuious processes, which cross each other at two-thirds 

 their length from the proximal end. The tumuli are pilose mesad with 

 long setse, which are thickly interlaced with each other. Th^ spinous 

 processes are also pilose mesad with long hairs to a point just beyond 

 their crossing. The spinous processes each bear lateral i^rocesses which 

 project cephalo-mesad and end in two spines, one short and acute, the 

 other long, slender, curved, and very acute. The spinous processes are 

 deeply bifid distad, and the space between the forks is filled with a thin 

 transparent membrane. 



There are three specimens in the collection, all from Bloomington 

 Townfehi}), Monroe County, Indiana. 



3. Polydesmiis erythropygus, var. Plate xii. 



This variety is very distinct in general ai)pearance from the typical 

 P. erythropygus, but does not deserve to rank as a species. 



Salmon pink, deeper on the caudal margins of the scuta and on the 

 lateral laminae, an indistinct dark mesodorsal line. Lateral laminae 

 separated by a space nearly equal to their width. The male genitalia 

 are formed as in erytliropygus, but have nothing of the " swan-ne(;k 

 curve," being straight, upright, and approximate. 



