Land Nemerteans.] SUBANTARCTIC ISLANDS OF NEW ZEALAND. 679 



average character of the " striped " group in being striped, in the large number 

 of proboscideal nerves (18), in the possession of an accessory lateral nerve, and 

 (possibly) in the possession of 4 disparate reserve stylet-pouches. 



G. caeca differs from any other known land nemertean in being totally blind. 

 It is also the smallest species of Geonemertes hitherto recorded. It seems to approxi- 

 mate most closely to G. australiensis, with which it agrees (possibly) in the number 

 of its proboscideal nerves, in the absence of striping (possibly), in the possession of 

 so many as 5 reserve stylet-pouches, and perhaps in the absence of eyes, if the diffuse 

 arrangement of these organs which is peculiar to G. australiensis may be regarded 

 as the first stage in their disappearance. It seems not unreasonable to regard any 

 departure from centralisation in an organ like the eye as an indication of ap- 

 proaching dissolution. 



