PYCNOGONIDA. 



essential reason for me to incorporate the two families has been the fact that Pallcnopsis which is 

 most closely related to the genus Pallcne, shows, by the formation of its palps that it will not do to 

 lay too much stress upon the presence or absence of these organs. 



I. Subfam. Nymphonini. 



Palpi expleti, pluries partiti. 



Palps well developed, with more joints. 



i. Gen. Nymphon (Fabr. 1794). 

 Nymphon, Wilson, Syn. Pycnog. New-Engl., 1878. 

 Chsetonymphon, Sars, Pygnog. bor. arct., 1888, pro parte. 

 Boreonymphon, Sars, ibid. 



The genus Nymphon with the limits which have been given to it here by Wilson, includes 

 a great number of species that might naturally be distributed to several groups, but the differences 

 seem to me to be too small to justify the division into more genera, or the separating of more or 

 fewer species of the genus Nymphon of Wilson. The genera Chatonymphon and Boreonymphon, 

 for inst, which have been separated by Sars, I.e. p. 352 and 354, seem to me too little characteristic 

 to be taken as more than groups of species, and with regard to N. macronyx which has been referred 

 to Ch&tonymphon, I think it even doubtful, if it might not more easily be placed among the species 

 that Sars still keeps as the genus Nymphon. 



The species of the genus, brought home by the Ingolf, may be arranged as shown in the 

 following analytical table, 

 a. The trunk naked. 



(The fingers of the chelae (i. e. both the immovable and the movable finger) dentate. 

 The auxiliary claws well developed), 

 b. The oculiferous tubercle pointed. 



b. b. The oculiferous tubercle truncate. 



c. The first tarsal joint shorter than the second. 



1. N. grossipes Fabr. 



2. N. Sluiteri Hoek. 



3. N. brevitarse Kr. 

 c. c. The first tarsal joint as long, or longer than the second. 



d. The two last joints of the palps short and thick. . 

 (The claws short, powerful. 



The fingers of the chelae short). 



4. N. serratum G. O. Sars. 



5. N. megalops G. O. Sars. 



6. N. Sarsii n. sp. 

 d. d. The two last joints of the palps long, thin. 



e. The claws short, powerful. 



7. N. Hoekii n. sp. 



8. N. Stroemii Kr. 



