CHAPTER XVI 



ARACHNIDA EMBOLOBRANCHIATA {CONTINUED) PALPIGRADI 



SOLIFUGAE = SOLPUGAE CHBRNETIDEA = PSEUDOSCOKPIONES 



Order IV. Palpigradi. 



Minute Arachnids tvifh three-jointed chelate chelicerae, and ivith 

 the last tiDO joints of the cephalothorax free. The abdomen consists 

 of eleven segments with a fifteen-jointed flagellum. 



In 1885 Grassi discovered, at Catania, a minute Arachnid which 

 did not fall into any of the established orders of Arachnida. 

 He named it Koenenia mirabilis. In 1893 Hansen collected 

 several specimens in Calabria, near Palmi and Scilla, and care- 

 fully redescribed the species in conjunction with Sorensen.^ It 

 has been studied still more minutely by Borner.^ 



There is a " head " portion, covered by a carapace, and bearing 

 the chelicerae, pedipalpi, and two pairs of legs. The two free 

 thoracic segments bear the third and fourth pairs of legs, recalling 

 the Schizonotidae (see p. 3 1 2), where the portion of the thorax bear- 

 ing these legs is separate, though covered by a single dorsal plate. 

 There are no eyes, but two hair-structures, believed to be sensory,, 

 are present on the cephalothorax, and Borner has observed open- 

 ings in the second joint of the first pair of legs which have all the 

 appearance of " lyriform " organs, as found in Spiders (see p. 325). 



The last three abdominal segments narrow rapidly, the last 

 bearing the anus. A fifteen-jointed caudal flagellum is carried. 

 Scorpion-like, above the animal's back. The body and tail are 

 each about a millimetre in length, and the animal is of a trans- 

 lucent white colour. 



The mouth is extremely simple, being merely a slit upon a 

 slight eminence. There are two sternal plates beneath the 

 " head," and one beneath each free thoracic segment. The 



' Ent. Tidsskr. xviii., 1897, p. 223, pi. iv. "^ Zool. An-, xxiv., 1901, p. 537. 



422 



