's RIJKS MUSEUM VAN NATUURLIJKE HISTORIE — LEIDEN. 17 



Auxiliary and main claws. The quotient varies between and -§-. 

 Most of the true PaMenopsis -species have small auxiliaries, and therefore the 

 quotient never attains \. On the other side Rigona possesses the longest 

 auxiliaries and the quotient never sinks under -J-. 



Eyes. A single species (8. P. ttjclemani Loman) has no eyes at all, 

 a few show small or rudimentary eyes, but the majority, even of the abyssal 

 forms, possess four eyes, the two foremost generally being larger than the 

 posterior ones. They are quoted in the list as „normal". Sometimes this last 

 characteristic has been disregarded by the authors, on the contrary they 

 emphatically describe the four eyes to be of a size. Yet I believe that in 

 all these cases closer inquiry and better examination will prove them to 

 be of a different size '). 



Male oviger. In my list the male ovigers are always called „normal", 

 i.e.: „robust, ten-jointed". The only exception to this rule has been 

 found in 1 3. P. spicata Hodgson, with a remarkable form of the male oviger 2 ). 

 But as only a single specimen of the species is known, we are not, 

 perhaps, allowed to entirely exclude accident or monstrosity. 



Female oviger. As „normal" I mentioned the ten-jointed, but much 

 weaker than in the males. Species, having fewer segments, coalesced by 

 ankylosis, are given apart. 



Legs, especially 1. Tibia. Some animals have hairless, smooth 

 legs ; others, we know, are grown over with very short hairs ; others again 

 show long, woolly or even feathered hairs ; a few, finally, are described 

 as possessing spiny feet. 



I have had an opportunity of comparing the length of the legs and 

 of the body, in several species. The latter has been measured from the 

 frontal margin in the middle line to the origin of the abdomen. The 

 result of this comparison is that there are species (4. P. californica 

 Schimkéwitsch) with excessively long legs, nearly eleven times longer 

 than the trunk, whereas for instance this quotient in 15. P. villosa 

 Hodgson comes to rather more than four and a half. There does not 

 seem to be a profound difference between the forms with a condensed 

 body and those with clearly visible segments. For the feet of Rigoyia are 

 much shorter and thicker, it is true, but in the same way the length 

 of the trunk diminishes, the quotient remaining unaltered. 



1) Compare Meinert, who has carefully reexamined the original type of P. fiuminensis in 

 the Copenhagen Museum. 



2) Caiman, The Pycnogonida of the „Terra Nova", 1915, p. 44. 



(24— 111-1916) 



