SOLIFUGAE. 831 



The mouth is situated at the end of the rostrum and is protected 

 by certain bristles which aid in conducting the fluid food to the 

 orifice. It opens into an oesophagus which traverses the beak 

 and pierces the nerve ganglion. This is triradiate in section 

 and can be expanded by the contraction of certain muscles, and 

 thus it forms a sucking apparatus. There are 110 salivary glands. 

 The oesophagus which is slightly coiled opens into the mid-gut 

 which runs straight back to the hind-gut. The mid-gut has 

 four pairs of the characteristic Arachnid pouches in the cephalo- 

 thorax and thorax ; the anterior two pairs are small, but the third 

 and fourth pairs penetrate into the ambulatory limbs. The 

 abdominal pouches, sometimes called the ' liver." are serially 

 homologous with those in front and occupy a very large space 

 in the abdomen : they open into two lateral diverticula which 

 communicate with the mid-gut. A pair of malpighian tubules 

 open into the same region of the alimentary canal in the fourth 

 abdominal segment. The hind-gut, which is lined by chitin, 

 bears dorsally a stercoral pocket as in spiders. 



The heart is a long tube, extending from the fourth or fifth 

 segment to the thirteenth, it has two pair of thoracic and six 

 pair of abdominal ostia. Anteriorly it ends in an aorta which 

 seems to discharge the blood on to the central nerve ganglion. 

 Posteriorly it commences as a vein. 



The respiration is trachea!. The position of the stigmata is 

 set forth above. The tracheae arising from one stigma com- 

 municate with those from the others. 



A pair of coxal glands form coiled masses behind the nerve 

 ganglion and open to the exterior between the coxae of the 

 third and fourth walking legs. 



In spite of the fact that in Galeodes the thoracic and abdominal 

 segments remain free, the nervous system is highly concentrated. 

 The supra-oesophageal ganglion supplies the chelicerae and 

 eyes, the sub-oesophageal sends nerves to the pedipalpi and 

 following appendages and other organs. Three nerves enter 

 the abdomen from the hinder border of this ganglion ; the median 

 of the three develops an abdominal ganglion ; this in the main 

 supplies the intestine, whilst the lateral nerves pass to the 

 generative organs. 



A small endosternite lies under the mid-gut just behind the 

 nerve mass, and a diaphragm, which is pierced by the heart, 



