DIPLOPODA 471 



Family 4. LYSIOPETALIDAE.* 



Like the Julidae, but with the first pair of legs only of the seventh 

 segment copulatory: 1 American genus. 



Lysiopetalum Brandt. Body long and slender, tapering gradually 

 to the hinder end ; seventh antennal joint conical and very short : 1 

 American species; several in Europe. 



L. lactarium (Say) (Fig. 730). Body with about 

 60 segments and 115 pairs of legs, yellowish-brown 

 in color with mottled darker spots and bands; eyes 

 with 40 ocelli connected by a black band; length 35 '^ 



mm.; width 2 mm.: common throughout the eastern 

 and central states. 



Family 5. , POLYDESMIDAE. 



(Fig. 726). Body more or less elongate, broad 

 and flattened, and with a hard integument, composed 

 of 19 or 20 segments and with 28 to 31 pairs of legs ; B 



the dorsal plate of each segment prolonged laterally peJaium^iactarfum 

 on each side to form a conspicuous wing; eyes absent; B^^^hfn'd ^'n^^^^i 

 antennae long; a row of stink glands on each side, body, 

 usually with a swelling around each; anterior pair of 

 legs only copulatory on seventh segment of male: 9 American genera 

 with about 50 species, all of which can roll themselves together. 



Key to the genera of Polydesmidae here described: 



Oi Basal portion of leg without spines. 

 6i Anal segment pointed behind. 

 Ci Dorsal plates flat, 

 di Each stink pore surrounded by a long, oval swelling; each segment 



with 2 or 8 transverse rows of tubercles 1. Polydesmus 



da Each stink pore surrounded by a round swelling ; each segment with 



4 or 5 rows of tubercles 2. Scytonotus 



Cj Dorsal plates convex and smooth 3. Leptodesmus 



62 Anal segment quadrate and smooth, or nearly so 4. Euryurus 



Cj Basal portion of legs with spines 5. Fontaria 



1. Polydesmus Latreille. Male with 30, female with 31 pairs of 

 legs ; each segment with 2 or 3 transverse rows of distinct tubercles ; each 

 stink pore surrounded by an elongated swelling; lateral plates large and 

 horizontal in position: 9 American species. 



P. serratus Say (P. canadensis Newport). Body brown, often red- 

 dish in color, about 37 mm. long; each dorsal plate with 2 rows of 4 

 rectangular tubercles in each; terminal spine of male copulatory ap- 

 pendage hook-shaped: common in tlie eastern and central states. 



* See "A Revision of the Lysiopctalidae," by A. S. Tackard, Proc. Am. Phil. See, 

 Vol. 21, p. 177. 



