CHELOPHORES, PALPI, ETC. 



507 



Fio. 268. — Proboscis 

 and chelophores of 

 Oordylochele longi- 

 collis, G.O.S. (After 

 Sars.) 



these the terminal portion or " hand " forms a forcipate " chela," 

 of which the ultimate joint forms the " movable finger." In 

 some species of Nymphon the chela is greatly 

 produced and attenuated, and armed with 

 formidable serrate teeth on its opposing edges ; 

 in others it is shortened, with blunter teeth ; 

 in Boreonymphon robustum the claws are 

 greatly curved, with a wide gape between. 

 In tins last, and in PhoxicJiilidium, the oppos- 

 ing edges are smooth and toothless. In Oordy- 

 lochele the hand is almost globular, the movable 

 finger being shortened down, and half enclosed 

 by the other. 



Palpi. — The second pair of appendages, or palps, are absent, 

 or all but absent, in the adult Pycnogonum, Phoxichilus, Plioxi- 

 chilidium, Pallene, and their allies. In certain of these cases, 

 e.g. Phoxichilidnim, a knob remains to mark their place ; in 

 others, e.g. Pallenopsis, a single joint remains ; in a few Pallenidae 

 a sexual difference is manifested, reduction of the 

 appendage being carried further in the female than 

 in the male. The composition of the palps varies 

 in the genera that possess them. In Xymphon 

 there are five joints, and their relative lengths 

 (especially of the terminal ones) are much used 

 by Sars in defining the many species of the genus. 

 The recently described Paranymphon, Caullerj', has 

 palps of six or seven joints. In the Ammotheidae 

 the number of joints ranges from five or six in 

 Tanystylum to nine (as a rule) in Ammothea and 

 Oorhynchus, or ten, according to Dohrn, in certain 

 species of Ammothea. Colossendeis and the Eury- 

 cididae have a ten-jointed palp, which in this last 

 family is very long and bent in zigzag fashion, as it is, by the way, 

 also in Ammothea. The terminal joints of the palp are in all cases 

 more or less setose, and their function is conjecturally tactile. 



Ovigerous Legs. — Custom sanctions for these organs an 

 inappropriate name, inasmuch as it is only in the males that 

 they perform the function which the name connotes.^ They 



1 As a rare oxoeption, Hoek has found the eggs carried on the ovigerous legs in 

 a single female o{ Jfymphon irevieaudatum, Miers. 



Fig. 269.— -E!«t/- 

 cide hispida, 

 Kr., showing 

 stalked pro- 

 boscis and zig- 

 zag palps. 



