86 A Guide to the Zoological Collections in the 



differ from spiders (i) in having stout pincer-like " cheli- 

 cerae"; (2) in having the segments of the abdomen all 

 separate and distinct, instead of fused together into a 

 single mass ; (3) in having only two eyes, instead of eight 

 or six ; and (4) in breathing by tracheae, instead of by 

 tracheal sacks or " lungs ^'. 



Galeodes is common in dry sandy regions like the 

 Punjab and Baluchistan. Its bite is very severe. 



vii.— ARACHNIDA ACARINA. (Mites and Ticks). 

 [mzQimx mr^ii-tnQz 58]. 



The Acarina form a large Order distinguished among 

 Arachnida by having the segments of the head, thorax, and 

 abdomen usually fused together into a single globular mass. 



The "chelicerae" and "palps" are often modified for 

 piercing and sucking; and the four pairs of legs are used 

 for crawling, clinging, and sometimes for swimming. Very 

 many of them are parasites. Various species of Ixodes 

 and Trombidium in Case 58 represent this order. 



viii.-AHACHNIDA PENTASTOMIDA. 

 [mtBimx ®aU-£ase 38]. 



The specimen of Pentastomum in Case 58 is a good ex- 

 ample of this small Order of parasitic and degraded Arach- 

 nids. 



In Pentastomum the body is quite worm-like, being 

 made up of a succession of rings without appen dages. 

 Even jaws are absent, their place being filled by two pairs 

 of chitinous hooks placed on either side of the mouth. 

 Pentastomum lives as a parasite within the nasal passages 

 of the Dog. 



5. ARTHROPODA PERIPATIDEA. 



[HJtstcrtt SEaU-rasc 63]. 

 This Class of air-breathing Arthropods contains the 

 single genus Peripatus, a specimen of the New Zealand 

 species of which is exhibited in Case 63. 



