— 149 — 



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



Fayn. i. Scutigeridae. 



Dorsal scuta 15 or more; lar.--i 3-joinlccl B. 



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



Feet-bearmg segments 20-25; antenna; 17 — 30-jointed 



Fd'in. 3. Scolopendridae. 

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

 ing v/ith a larger Fam. 4. Lithobiidae. 



Family i. SCUTIGERIDAE Gervais. 

 The family Scutigeridae consists of a single genus Scuiigera 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 6'. Linceci {Cerma 

 tia Linceci \W ood) 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; antennae approximate 



Mecistocephalus Newport. 4 sp. 



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



B.— Cephalic segment subquadrate; joints of antennae unequal 



Geophilus Leach. 6 sp. 



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

 proximate Strigamia 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 ; antennce attenuate, 17 — 30-jointed 



Scolopendra Newport. 9 sp. 



Eyes wantnig B. 



B. — Feet-bearing segments 21 , C. 



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



Scolopocryptops Newport. 4 sp. 



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



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



* The genus Theatops Newport founded on Crypiops pnsiica Say is doubtless a 

 form of Scolopendra. (^Cj'JiS Zl- J~ ■__ 



ENTOMOLOGICA AMERICANA 23 



