Capt. F. W. Ilutton on Peripatus iiovai-zealaiidite. 365 



size posteriorly and are much larger immediately behind the 

 head. The only other trachea that I have found is a large 

 one opening on the ventral surface behind the mouth, and 

 with branches embracing the oesophagus. The trachege are 

 long, slightly branched, and radiate from a short common 

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

 those of the Tracheata. The sheath is distantly longitudinally 

 striated. The spiral 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 

 the common trunk is about "0026 inch. The tracheas never 

 anastomose with one another. 



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

 side above the nerve-cord (PI. XVII. fig. 1, 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 have 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 yelloAV colour, 

 and '001 inch or less in diameter. 



Nervotis System. — Consists of a large bilobed cephalic 

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

 anterior nerves passing into the antennse, 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 (PL XVII. fig. l,e), passing over the oviducts near 

 the vulva (fig. 8,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 portion ; but they are here more delicate^ and I 

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

 brown pigment-spot seated on a slight prominence of the 

 cephalic ganglion. The epidermis is continued over the eye, 

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



