Volume //.] February, ryoi. \.\ ',>. 



BIOLOGICAL BULLETIN. 



NOTES ON THE HABITS OE PYCNOGONIDS. 1 



J. COI.K. 



THE Pycnogonids constitute a small and well-defined group, 

 especially interesting on account of their peculiar and unique 

 structure. In general they have been largely neglected by 

 naturalists, especially as compared with some other groups. 

 but they have received considerable attention from specialists, 

 and several excellent monographs have appeared dealing with 

 their structure and classification ; in fact, all the literature of 

 the group is very largely systematic or strictly morphological. 

 The embryology has been worked out for some forms by Dohrn 

 and Hoek, and in this country by Morgan, 2 who has also given 

 an extended account of the metamorphosis of Tanystylum, and 

 considerations on the phylogenetic position of the Pycnogonida. 3 

 The principal systematic work in this country has been done 

 by Wilson, 4 who described some fifteen species found on the 

 New England coast. Practically nothing has been written on 

 their habits, which ought, it would seem from the isolated 

 position of these animals, to offer some very interesting com- 

 parisons with those of other arthropods. An excellent oppor- 

 tunity for this work was offered during the past summer at the 



1 From the Zoological Laboratory. University of Michigan. 

 - Morgan. T. H.. A Contribution to the Embryology and Phylogeny of the 

 .ogonids Biol. Lab. J. Hopkins Unh-. V.. No. i. pp. 1-76. 1891. 



3 Morgan. T. H.. he. cit., and "The Relationships of the Sea-Spiders," Biol. 

 Lfct. .^farinf Biol. Lab. for 1890. Seventh Lecture, pp. 142-167. 1891. 



4 Wilson. E. B. (a) A Synopsis of the Pycnogonida of Xew England," 

 Trans. Ccnn. Acad. V.. pp. 1-26. i $78. (p\ "The Pycnogonida of Xew Eng- 

 land and Adjacent Waters," C. S. Fish Com. Reft, for 1878, pp. 463-506. 1880. 



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