BRYOZOA OP WOODS HOLE REGION. 213 



Family PEDICELLINID Hincks, 1880. 



Zooecium pedunculate on a stalk which has one or two contractile regions and which rises from a 

 creeping stolon; body separated from stalk by a diaphragm, deciduous, a new body regenerating in place 

 of the one cast off; lophophore terminal and transverse. 



KEY TO GENERA. 



1. Peduncle not abruptly enlarged at the base near the junction with the stolon Pedicellina. 



2. Peduncle abruptly enlarged at the base Barentsia. 



Genus PEDICELLINA M. Sars, 1835. 

 Pedicellina cernua (Pallas). [PI. xvni, fig. 3, ^a, $b, $c, and 3d.] 



Pallas 1771, p. 57 (Brachionus cernuus). 



Leidy 1855, p. 143 (Pedicellina americana). 



Verrill and Smith 1874, p. 707 (P. americana Leidy). 



Verrill 18790, p. 31 (P. americana and eckinala). 



Jelly 1889 (? P. nulans Dalyell). 



Ehlers 1889, p. 141 (=? P. glabra Hincks). 



Jullien 1888, p. 13 (P. hirsuta). 



Cornish 1907, p. 79. 



Stolon slender, more or less transparent, branching. Body cup-shaped, usually with a well-marked 

 gibbosity on one side, tentacles 14 to 24. Peduncle stout, tapering gradually at its upper end. Stout 

 spines often present on both stalk and body, or on either, or entirely absent from both. Abundant in 

 certain situations, as on the piles of docks, where it commonly grows intermingled with other creeping 

 forms. It occurs also at some depth in Vineyard Sound, and I have taken it once at Crab Ledge in 18 

 fathoms. 



A comparison with European material shows that our species is undoubtedly the same as cernua. 

 Concerning the species in Europe there has been much difference of opinion. Ehlers (1. c.) makes three 

 species out of it, P. glabra Hincks entirely without spines, P.echinta Sars with spinous peduncle, and 

 P. hirsuta Jullien with spinous body, although he recognizes the possibility of their belonging 

 together. Hincks and Joliet had already noticed the variability in the spines, and Hincks men- 

 tioned the smooth form merely as a "variety glabra." In American specimens is exhibited the whole 

 range of variability in number and arrangement of spines, and there is such an amount of variation 

 among the individuals of a single colony that I am convinced no separation based upon their presence 

 or absence can be of specific value. Leidy's P. americana, along with glabra, echinata, and hirsuta, 

 must be considered synonyms of cernua. 



I have collected the species, exhibiting the variation in spines, at Beaufort, N. C. , and at the Tortugas, 

 Fla. Hincks (1889) has recorded P. nutans Dalyell from the Gulf of St. Lawrence, but I have failed to 

 find it in the Woods Hole region. 



Genus BARENTSIA Hincks, 1880. 



Similar to Pedicellina in the form of the body and stolon; the stalk differing from that genus in being 

 suddenly expanded near the base into a muscular organ for swinging the stalk from side to side; stalk 

 above the enlargement more slender than in Pedicellina. 



KEY TO SPECIES. 



1 . Stalk without areolae or perforations major. 



2 . The cuticle of the stalk with rounded areolae or perforations discreta. 



Barentsia major Hincks. [PI. xvni, fig. 4.] 



Hincks 1888, p. 226. 



Jullien and Calvet 1903, p. 27 (B. elongata.) 



Stolon rather stout, creeping, jointed at intervals. Pedicels of great length, very slender below and 

 expanding somewhat above, delicately ringed, of a very light horn color, rising from a stout cylindrical 



