NO. 1933. BRYOZOA FROM EASTERN NORTH AMERICA— OSBURN. 283 



MUCRONELLA PR.£LnCIDA Hlncks. 

 Plate 34, figs. 3, 3a, and 3c. 



Localities. — Shoal Tickle, Labrador, one very young colony on the 

 stem of Myriozoum coarctatum; halfway from Mugford to Hebron, 

 Labrador, one mature specimen with zooecia and avicularia. 



Hincks described this species in his Polyzoa of the Queen Charlotte 

 Islands (1882, p. 255) and again commented on it in the Polyzoa of 

 the St. Lawrence (1888, p. 225). He evidently had not seen the ovi- 

 cells in either the Pacific or Atlantic specimens. One specimen in 

 my possession has these well developed. They are subglobose, 

 rather rough, punctured, prominent, and when adult the secondary 

 raised peristome of the zooecium is continued upon the front of it like 

 a raised rib. In his original description Hincks states that there are 

 no avicularia though the figure accompanying the description seems 

 to indicate their presence. Later, in his St. Lawrence paper, he is 

 careful to state in regard to these ''peculiar projections placed one on 

 each side of the cell at the base of the raised peristome," that "these 

 have much the appearance of avicularia but really are not such." 

 These structures he failed to fuid in the St. Lawrence specimens. In 

 the specimens collected by Doctor Bryant these structures are spar- 

 ingly represented, and some of them are undoubtedly avicularia with 

 hinged mandibles, while others seem to have the mandibles sup- 

 pressed. In fact, in some cases there are merely oblong membranous 

 areas where the avicularia have failed to develop. In my prepara- 

 tions mounted in balsam the structure of the avicularium is unmis- 

 takable. 



MUCRONELLA VENTRICGSA (Hassall), 

 Escharoides cocdnea var. ventricosa Verrill, 18796, p. 31. 

 Locality. — Shoal Tickle, Labrador, rare, on shells. 



PORELLA CONCINNA (Busk). 



Lepralia rubens Stimpson, 1853, p. 19. 



Lepralia belli Dawson, 1859, p. 256. — Packard, 1867, p. 271. 



Discopora cocdnea Rink, 1877, p. 444. 



Porella Isevis var. condnna Verrill, 18796, p. 30. 



Localities. — Fourteen miles south of Cape Sable, scarce; St. Pierre 

 Bank, Newfoundland, a few on Pecten shells; oft' Cape Race, New- 

 foundland, encrusting dead Buccinum shells; Shoal Tickle, Labrador, 

 one small colony on a pebble. 



PORELLA SACCATA (Busk). 



Plate 34, fig. 4. 



Eschara elegantula Packard, 1863, p. 411; 1867, p. 275.— Rink, 1877, p. 444. 



Eschara papposa Packard, 1867, p. 270. 



Porella elegantula Verrill, 18796, p. 30. — Whiteaves, 1901, p. 104. 



Localities. — South by east from Burin, Placentia Bay, Newfound- 

 land, a few fragments; off Cape Race, Newfoundland, scarce; Shoal 



