Vol. XVII November, /pop. No. 6 



BIOLOGICAL BULLETIN 



NEW AND LITTLE KNOWN HYDROIDS OF 

 WOODS HOLE. 1 



CHAS W. HARGITT. 



During the summer of 1907, while engaged upon certain 

 problems associated with the work of the biological survey carried 

 on at the Fisheries Laboratory, I described several hydroids, 

 some new, others more or less rare, in a paper published in the 

 BIOLOGICAL BULLETIN, January, 1908. During the following 

 summer I was fortunate in finding a few others which, like the 

 former, were in part new and in part hitherto unknown within 

 the locality, and in one case at least, wholly new to American 

 fauna. In the following account will be found such descriptions 

 as seem called for in order to bring them definitely to knowledge 

 as integral factors of the hydrozoan fauna of the region con- 

 cerned. 



Cf.ADOCORYNE FLOCCOSA Var. SARGASSENSIS. 



In a mass of Sargasswn which was picked up during the 

 summer of 1907 in Vineyard Sound, bearing a rich hydroid 

 fauna, I found a very minute hydroid which at first greatly 

 puzzled me. It was intricately associated with other species, 

 particularly with AglaopJicnia minuta, and at first seemed to be a 

 sort of nematophoric accessory of this hydroid, the small round 

 heads of young specimens bristling with nematocysts having but 

 little resemblance to an independent hydroid. But a more 

 extended examination brought to light other and larger speci- 

 mens, and soon it was found that the thing under examination 

 was beyond doubt a very minute and apparently unknown species 

 of hydroid. A series of developmental stages were found giving 

 all conditions, from minute buds just arising from the stolon- 



1 Contributions from the Zoological Laboratory, Syracuse University. 



369 



