Capt. F. W. lluttniin// IVripatiis iiova'-zcalaiulijo. ',U\') 



size |)ost(M-loily and arc much larf^cr iimncdiatcly l^cliiiid the 

 head. The only other trachea that 1 have found is a hirj^e 

 one oj)eninj^ on the ventral suriaee behind the inoutli, and 

 "vvith branches enibracinii; tlie (csojihai^us. The traclieiii arc 

 loni^, sliuhtly branched, and radiate troni a short common 

 trunk. There are no stigmata on the surface at all resembling 

 those of the Tracheata. The slieatii is distantly longitudinally 

 striated. The s])iral fibres are rough, striated, and very irre- 

 gular; they never form close spiral rings as in insects. The 

 trunk of a trachea contains numerous fibres, which are con- 

 tinued into the branches and generally end singly or two 

 together (PI. XVII. fig. 5). The diameter of a branch from 

 tlie common trunk is about "0020 inch. The trachea3 never 

 anastomose with one another. 



Circulatory System. — This consists of a vessel lying on each 

 side above the nerve-cord (Pi. XVII. fig. l,c); they are 

 uniform in thickness throughout the whole length of the 

 animal. The walls of these vessels are extremely delicate 

 and difficult to detach from the muscular layer ; but they are 

 easily demonstrated in transverse sections of a specimen har- 

 dened in alcohol. I iiave not been able to trace their termi- 

 nations at either extremity. When the animal is contracted, 

 the interior wall is thrown into transverse folds. They are 

 filled with granulated cells of a pale greenish yellow colour, 

 and 'OOl inch or less in diameter. 



Nervous System. — Consists of a large bilobed cephalic 

 ganglion (PI. XVII. fig. 6), which gives origin to a pair of 

 anterior nerves passing into the antennae, and posteriorly to 

 two large nerve-cords, "013 inch in diameter, which pass down- 

 ward on either side of the oesophagus and then approach each 

 other to the bases of the first pair of ambulatory legs, where 

 they are connected by a strong commissural cord below the 

 oesophagus ; they then gradually diverge again, passing back- 

 ward, just over the insertion of the legs, to the posterior ex- 

 tremity (PI. XVII. fig. 1,^), passing over the oviducts near 

 the vulva (fig. S,d). The cord is slightly waved in outline, 

 but has no ganglia : it sends off opposite branches at about 

 •01 inch distance, or about nine between each pair of legs ; 

 these branches are about "002 inch in diameter (PI. XVII. 

 fig. 7). In the anterior portion of the body these branches 

 connect the two nerve-cords ; and they probably do so also in 

 the posterior j)ortion ; but they are liere more delicate, and I 

 have not been able to trace them. Tiie eye consists of a single 

 brown ])igment-spot seated on a slight ])rominence of the 

 cephalic ganglion. The epidermis is continued over the eye, 

 but it is here translucent and almost colourless. The nerve- 



