REPORT ON THE PYCNOGONIDA. 



147 



ledge of the species of Pycuogouida known to occur on the coasts of New England and 

 Nova Scotia. With two exceptions {Achelia scabra, Wilson, and Nymphon macrum, 

 Wilson) the species here described are the same as those of a former paper by Mr Wilson, 

 published in the Trans. Connect. Acad. Sci., vol. v. pp. 1-26, 1880. The new Achelia 

 is quite unknown to me, but Nymphoa macrum, Wils., is undoubtedly the species 

 which. I have described in my report (p. 45) as Nyinp>}ion brevicollum. The Challenger 

 specimens were taken south of Halifax (83 fathoms), those described by Mr Wilson 

 in the Gulf of Maine (85 to 115 fathoms). 



The other paper (Reports on the Results of Dredging, under the Supervision of 

 Alexander Agassiz, along the East Coast of the United States, during the summer of 1880, 

 by the United States' Coast Survey Steamer " Blake," Commander J. R. Bartlett, U.S.N., 

 commanding, xiii. Report on the Pycnogonida, by Edmund B. Wilson ; Bulletin of 

 the Museum of Comparative Zoology at Harvard College, vol, viii.. No. 12, Cambridge, 

 Mass., March 1881, pp. 239-256, pis. i.-v.) contains descriptions of. ten species of Pycno- 

 gonids, five of which are new. These belong to three genera, two of which are con- 

 sidered by the author as new. ' The new species are in the first place two species of 

 Colossendeis, Jarzynsky, Colossendeis colossea, and Colussendeis macerrima. Then a 

 new genus Scaeorhyiichiis, with the species Scaeorhynchus armatus, is proposed ; finally, 

 the new genus Fallenopsis, with the species Pcdlenopsis forjicifer and Pallenoims 

 longirostris, is described. The descriptions are illustrated by very good figures. On 

 comparing these figures and descriptions with those of my report, there can be little 

 doubt that Colossendeis colossea and C. imtcerrimo/ are very nearly related to, if not 

 identical with, my Colossendeis gigas and C. leptorhynchus. As to the genus Scaeo- 

 rhynchus, I do not think there are suSicient grounds for separating it from Ascorhynchus, 

 G. 0. Sars. Neither the presence of dactyli on the first pair of legs, nor the structure 

 of the rudimentary mandibles (antennae) makes it proper to separate these genera : 

 Scaeorhynchus (like Gnamptorhynchus, Bohm) is only a synonym of Ascorhynchus. 

 The species armatus, Wilson, seems to be different from those hitherto described, and 

 also from those of the present report. 



The new genufi Palleno'psis is intended to embrace those species which come near to 

 Phoxichilidium, but which are characterised by ten-jointed accessory legs present in both 

 sexes, and by three-jointed mandibles. Three (perhaps four) species described in my 

 report show these characters also, and (pp. 82 and 88) I have been long in doubt whether 

 I should not propose a new genus for these species. I did not take the step because I do 

 not wish to augment the number of genera more than necessary until our knowledge 

 of generical characters is more perfect. Mr Wilson is not so slow in proposing new 

 genera ; in the present instance, I believe, however, that his proposal has a fair chance of 

 being accepted. The two species described by Mr Wilson are, I believe, difi"erent from 

 those described in my report. 



WOODS 

 HOL-E, 

 MASS. 



