— 149 — 



A. — Dorsal scuta 8; antenna? long, setaceous; legs long; tarsi many-jointed 



Fain. I. Scutigeridae. 



Dorsal scuta 15 or more; tar^i 3-jointed B. 



B. — Feet-bearing segments 40 — 150; antennae 14-jointed Fam. 2. Geophilidae. 



Feet-bearing segments 20—25; antenna: 17 — 30-jointed ' 



Fam. 3. Scolopendridae. 

 Feet-bearing segments less than 20; dorsal scuta in two sets, a smaller alternat- 

 ing with a larger Fam. 4. Lithobiidae. 



Family 1. SCUTIGERIDAE Gervais. 

 The family Scutigeridae consists of a single genus Scutigera Lam., 

 better known as Cermatia which is a more recent name. Two species 

 are found in the United States: S. forceps [Cermatia forceps Wood) some- 

 what generally distributed east of the Mississippi, and £. Linceci (Cerma 

 tia Linceci Wood) from Texas. I have found the former at Bloomington, 

 111., Philadelphia, Pa., Brooklyn and Utica, N. Y. In Brooklyn it ap- 

 pears to be somewhat common in cellars. In Utica a single specimen 

 was taken running about the floors of the N. Y. Central station. 

 Family 2. GEOPHILIDAE Leach. 

 The Geophilidae of North America are divided among three genera 

 as follows: 



A. — Cephalic segment elongate; twice as long as broad; antennas -approximate 



Mecistocephalus Newport. 4 sp. 



Cephalic segment less than twice as long as broad, subquadrate or triangular.. B. 



B. — Cephalic segment subquadrate; joints of antennas unequal 



Geophilus Leach. 6 sp. 



Cephalic segment narrowed in front; body attenuate anteriorly; antenna? ap- 

 proximate Stngamia Gray. 16 sp. 



Family 3. SCOLOPENDRIDAE Newport. 



This family contains the species popularly known and sometimes 



foolishly dreaded as "centipedes"; our genera are four in number and 



may be distinguished as follows.* 



A. — Eyes distinct; feet-bearing segments 21 ; antennas attenuate, 17 — 30-jointed 



Scolopendra Newport. 9 sp. 



Eyes wantmg B. 



B. — Feet-bearing segments 21 , C. 



Feet-bearing segments 23; last segment narrow; antennae 17 -jointed 



Scolopocryptops Newport. 4 sp. 



C— Last scutum the largest, quadrate , Opisthemega Wood. 2 sp. 



Last scutum not larger than the others Cryptops Leach. 3 sp. 



* The genus Theatops Newport founded on Cryptops poslica Say is doubtless a 

 form of Scolopendra. 



ENTOMOLOGICA AMERICANA 23 



