Introduction to Animal Morphology. 375 



two slightly curved rows of ocelli. Some (§Orbitelae) spin 

 geometrical webs, in whose middle they lurk ; their first and 

 second pairs of legs are longer than the fourth, and they have 

 eight ocelli either in two transverse lines (Tetragnatha), or 

 the four medial in a square, and the lateral on the edge of 

 the cephalothorax (Epeira). Gasteracantha, Mithras, and 

 Acrosoma (S. American), have the abdomen very broad, and 

 often with long lateral horns. Other Spiders are either La- 

 terigradae, spinning single threads, living in web-united clus- 

 ters of leaves, and moving sideways (Thomisus), or else 

 Insequitelae, resembling Thomisus in having the first pair of 

 legs the longest, but spinning irregular webs, whose threads 

 cross each other in inconstant directions, as in Pholcus, which 

 has its outer, or Theridion, which has its inner, ocelli the 

 largest. Family 2. Lycosidae — wandering or hunting Spiders, 

 spinning no webs, but the females carrying egg-sacs ; ocelli 

 in three rows ; some have a cephalothorax narrowing in front, 

 with the second (Dolomedes), or fourth (Lycosa, the Taran- 

 tula) pair of legs the longest. Others have a square cephalo- 

 thorax, and leap on their prey (Salticus, Eresus). Myrmecia 

 is ant-like in shape. 



Order 3. Arthrogastra"' {Gerstaecker) — abdomen sessile, 

 segmented ; mandibular palps developed as pincers or cheli- 

 cercE. They are divided into five Sub-orders, each containing 

 a single family. 



1. Phalangita {Gersf.) Opilonidea (Harvest-men) — short- 

 bodied ; abdomen thick, transversely folded, or six-jointed ; 

 cephalothorax unsegmented ; respiration tracheal ; chelicerse 

 three-jointed, with no poison gland ; ocelli two (the so-called 

 hinder pair are said by Krohn to be gland sacs) ; third and 

 fourth feet two-clawed ; first and second, one-clawed. The 

 female has an ovipositor. Hermaphrodites have been found 

 producing small ova in the lobes of the testis. They hunt 

 their prey. Cyphophthalmus is a blind cave-dweller, with 

 eight abdominal rings. The hind legs are often, in S. Ame- 

 rican forms, large and curiously bent (Gonyleptes). Trogu- 

 lus and Phalangium are European. 



2. Pseudoscorpiones {Latreille) — small, flattened, cylindri- 

 cal, or pear-shaped ; abdomen eleven-jointed, with spinning 



