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, backw^ards, or sideways; 3 families with 100 



species. 



Key to the families of Pseudoscorpionida here described : 



Qi Cephalothorax with a transverse suture ; two eyes or none usually 



present 1. Cheliferidae 



Cj No such suture ; four eyes usually present 2. Obisiidae 



Family 1. CHELIFERIDAE. 



Spinneret on mandible long and tubular; serrula attached along its 

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



1. Chelifer Geoffroy. 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). Leng-th 3 mm.; color' 

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



Fig. 645 Fig. 646 



Fig. 645 — Chelifer 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. 



