132 



DISCOVERY REPORTS 



indication of a median reversed claw between these two auxiliaries. The outer, or dorsal, 

 is probably the original auxiliary, since it is on a level with and subequal to the auxiliary 

 on the posterior side. The inner, additional auxiliary is very small. 



6. The female of Nymphoii temdpes, Bouvier (p. 38), is interesting in that the two 

 anterior pairs of walking legs are shorter and 

 much more slender than the two posterior 

 pairs and do not contain developing ova. It 

 is possible that all four anterior legs were lost 

 and subsequently regenerated, although the 

 loss of so many legs at one and the same time 

 would be a rare occurrence. It is just possible, 

 of course, that the original specimen was cut 

 in two halves and that the whole anterior por- 

 tion of the body was regenerated. This is highly 

 improbable, however, for Loeb (1895, p. 251), 

 experimenting with Phoxichilidiiim maxillara, 

 found that "Bei den aboralen Halften konnte 

 ich dagegen nur eine Anschwellung am vor- 

 deren Endewahrnehmen". The trunk, chelo- 



phores, palps and ovigers are all apparently quite normal and show the normal relative 

 proportions ; if the whole anterior half of the body had been regenerated it would very 

 likely have been small in proportion to the posterior half. Another possible explanation 

 may be advanced tentatively, namely, that in this species the female has normally only 

 two pairs of genital openings as in the male ; but until more females are available the 

 specimen may be regarded as somewhat abnormal. 



Fig. 75. Nymphon procerot'des, BouYier. Co-type. 

 Ventral view of left palp. 



ENCRUSTING ORGANISMS 



Encrusting organisms are found on Pycnogonida with far greater frequency than on 

 Crustacea, for example. These are chiefly encrusting Polyzoa, adherent Foraminifera 

 and Hydroids ; but, in addition, an occasional Brachiopod, Sponge, Tunicate, Serpulid 

 and Cirripede {Scalpelhtm) may be attached. Occasionally, also, one or two Isopods 

 may be found clinging to a Pycnogonid. 



From the abundance of encrusting Polyzoa found on Decolopoda antarctica, compared 

 to those on D. mistralis, it is evident that the former must be a more sluggish species 

 than the latter (see list below). Polyzoa are also found growing on five species of 

 Ammothea — e.g. the specimen of A. striata from St. 167 has very large patches of 

 Alcyonidium entirely covering a number of the long segments of the legs. Perhaps these 

 species are also rather sluggish, but the numbers of individual specimens are too small 

 to enable one to be at all dogmatic on this point. With the exception of Colossendeis 

 glacialis, the remaining species on the list are each represented by a large number of 



