PSEUDOSCORPIONIDA 409 



shaped serrula (Fig. 645, B), and with long scorpion-like pedipalps; legs 

 long, 5-jointed, and ending with 2 claws; eyes present or not; respiration 

 by tracheae, 2 pairs of spiracles being present on the second and third 

 abdominal segments ; genital pore in the second abdominal segment, in the 

 female surrounded by cement glands, the secretion of which serves to fasten 

 the eggs to the body of the mother ; silk glands open to the outside near the 

 tip of the movable finger of the mandible; the animals spin nests, in 

 which they spend the winter or can retire during a moult ; no poison glands 

 present: under the bark of trees, among moss or dead leaves, or in 

 houses, on old books, or furniture, where they eat mites and small insects; 

 occasionally they attach themselves for purposes of migration to insects; 

 they run rapidly forwards, backwards, or sideways; 3 families with 100 

 species. 



Key to the families of Pseudoscorpionida here described: 



<! Cephalothorax with a transverse suture; two eyes or none usually 



present 1. CHELIFEBIDAE 



o, No such suture ; four eyes usually present 2. OBISIIDAE 



FAMILY 1. CHELIFEKIDAE. 



Spinneret on mandible long and tubular; serrula attached along its 

 whole length; 2 eyes or none present: 5 genera. 



1. CHELIFER Geoffrey. Cephalothorax triangular, rounded in front 

 and divided by transverse sutures into 3 parts; 2 eyes present; man- 

 dibles small: several species. 



C. cancroides (L.). Book scorpion (Fig. 645). Length 3 mm.; color 

 reddish-brown; dorsal abdominal plates divided by a median line; basal 



Fig. 645 Fig. 646 



Fig. 645 Chelijer cancroides. A, dorsal aspect (Leunis) ; B, mandible (Comstock). 

 Fig. 646 Chelanops oblongus (Berger). 



portion of pincer thick, terminal finger curved: often found in houses 

 on old books, furniture, or clothing; cosmopolitan. 



C. biseriatum Banks. Body 2.2 mm. long, pale yellowish in color, 

 with 2 rows of dark spots on the abdomen; pedipalps very slender; no 

 large granules on Cephalothorax : Florida ; Ohio ; Jamaica. 



