PALPIGRADI. 829 



pierced by the oesophagus. The supra-oesophageal ganglion, 

 which is very large, supplies nerves to the median and lateral 

 sense organs and to the chelicerae ; the sub-oesophageal shows 

 swellings corresponding with the remaining five pair of appen- 

 dages, and it is connected with a single abdominal ganglion 

 lying in the second and third segment of that region. 

 The ovary is unpaired. It is prolonged anteriorly into two 

 oviducts which swell out and fuse in the second abdominal seg- 

 ment ; the vagina so constituted opens on the second abdominal 

 segment. There is also a receptaculum seminis. 



The primitively paired condition of the reproductive organs 

 is retained in the testis. The paired tubular testes end anteriorly 

 in much coiled vasa deferentia which enlarge to form vesiculae 

 seminales. There are numerous accessory glands. The vasa 

 deferentia open also on the ventral surface of the second abdo- 

 minal segment. The spermatozoa are said to be immotile. 

 Nothing is known of the embryology and but little of the young 

 stages through which the animals pass before becoming adult. 

 They occur under stones where a certain amount of moisture, 

 which they seem to need, is usually retained. 



There is but one family. Fam. Koeneniidae, with the characters of 

 the Order. Prokoenenia with the so-called lung-sacs. Prokoenenia wheeleri 

 from Texas and P. chilensis from Chili. Eukoenenia without the lung 

 sacs ; Eukoenenia mirabilis, Sicily, Italy, Tunis, Eukoenenia siamensis 

 Siam ; E. augusta, E. ftorenciae Texas, and E. grassi South America. 



Order 5. SOLIFUGAE (SOLPUGAE) * 



Cephalothorax (prosoma) covered by three fused segments followed 

 by three free thoracic segments ; the abdomen is not constricted 

 and consists of ten segments ; the chelicerae are chelate, the 

 pedipalps leg-like ; respiration tracheal ; on the basal joint of the 

 fourth legs are 3-5 racquet-shaped organs, the malleoli. 



The segmentation of the Solifugae body approaches that of 

 Insects inasmuch as there occurs a distinct head, thorax and 



* Kraepelin, Das Tierreich, 12 Lff., Pedipalpi u. Solifugae, Berlin, 1901 ; 

 and Bernard, The Comparative Morphology of the Galeodidae, Tr. Lin. 

 Soc,, London, 2nd Ser., vi, 1894-97, p. 305. . 



