ATLANTIC AND CARIBBEAN PYCNOGONIDA—HEDGPETH 167 
south of the Cape. The species known to occur regularly on both 
sides of this limitmg promontory are Pycnogonum litiorale, Phoxi- 
chilidium femoratum, Nymphon grossipes, and Achelia spinosa. Three 
of these are ubiquitous Boreal species whose southern limit seems to 
be Long Island Sound.°® 
/ Northern Jimit of 
ak “ warm water convergence 
O Anoplodactylus petiolatus 
X Endets spinosa 
Ficure 7.—Occurrence of pycnogonids on sargassum in the mid-Atlantic 
(after Timmermann, fig. 3). 
The pyenogonids of Woods Hole are notably few. Only three 
species are common in that locality: Tanystylum orbiculare, Cal- 
lipallene brevirostris, and Anoplodactylus lentus. The last two have 
been reported from the Bay of Fundy, but both records are of single 
specimens. They can be considered accidental vagaries if not errors 
in identification or labeling. All three species are widely distributed 
southern forms, and Woods Hole represents their northern optimum 
limit. The pelagic sargassum species Endeis spinosa occurs sporadi- 
cally at Woods Hole when sargassum drifts into that region. Curiously 
enough, Anoplodactylus petiolatus has not been collected at Woods 
Hole, although it seems to be more common in floating sargassum 
than Endeis spinosa is (fig. 7). 
6 Stephensen’s (1933) record of P. littorale from Barbados is not supported by the collections examined; 
it may be a result of mislabeling. 
