476 



MYRIAPODA 



T. postica (Say) (Fig. 736). Body about 45 mm. long, reddish in 

 color; anal legs close together and parallel, with the tips crossing, their 

 basal position without spines: eastern and central states, north to 

 Virginia and Illinois, often very common. . 



4. ScoLOPOCRYPTOPS Newport. Number of legs 23; 

 / 10 or 11 pairs of spiracles; eyes absent; cephalic dorsal 



plate extends back over the first segment, which has no 

 transverse suture; antennae 17-jointed: 4 American 

 species. 



5. sexspinosa (Say). Body 65 mm. long, reddish in 

 color; feet yellow; antennae yellow and hairy; basal por- 

 tion of anal legs with 2 large spines (inner one sometimes 

 atrophied in northern specimens) ; cephalic plate mar- 

 ginate; anterior margin of the lower lip (basal portion 

 of maxillipeds) nearly straight, not toothed: entire United 

 States, often very common. 



Fig. 736 

 Theatops pos- 

 tica (Wood). 



/ 



Family 3. LITHOBIIDAE. 



Body with 15 leg-bearing segments, of which 9 are large and 6 

 (segments 2, 4, 6, 9, 11, and 13) small, the anterior segment bearing the 

 maxillipeds and the anal segment being without appendages; with 15 

 pairs of legs, in the coxae of the last 4 pairs of 

 which are the openings of coxal glands; eyes com- 

 posed of usually many ocelli; maxillary palp 

 3-jointed; young born with 7 pairs of legs: 10 

 genera, with about 250 species, about 50 species 

 being American. 



LiTHOBiTTS Leach. Spiracles on segments 3, 5, 

 8, 10, 12, 14, and sometimes also 1; coxa of maxilli- 

 peds with 2 to 8 teeth on each side; antennae with 

 usually 20 to 50 joints: over 200 species, about 47 

 American. 



L. forficatus (L.) (Fig. 737). Body about 28 

 mm. long, anal legs 10 mm. long; color brownish or 



IeI 



m 



^ 



Fig. 737 Fig. 738 



Fig. 737 — Lithohius 



forficatus (Wood). 



Fig. T.".S — Lithohius 



muUidentatus 



(Wood). 



yellowish; antennae half as long as the body, with 

 33 to 43 joints; ocelli 23 to 48 in number; posterior angles of dorsal 

 plates 9, 11, 13 elongated: the entire country; Europe; South America; 

 often very common. 



L. multidentatus Newport (Fig. 738). Body about 25 mm.; anal 

 legs 10 mm. long; color brown; antennae short, with 19 to 23 joints; 

 ocelli 27 to 35 in number; posterior angles of dorsal plates 6, 7, 9, 11, 13 

 elongated: eastern and central states; common. 



