226 BULLETIN OF THE BUREAU OF FISHERIES. 



strongly decurved beak. Ovicell situated directly above the cell, the stalk broad, form hemispherical 

 or somewhat hood-like, the opening \vide and directed forward and downward. A considerable 

 amount of variation is noticeable in the form of the cell and in the development of the spines. The 

 ovicells in our specimens are more open than Hincks figures them in the English specimens, but the 

 differences are not sufficient to warrant a separation, in my opinion. 



Yerrill has recorded the species from Vineyard Sound at 6 to 8 fathoms. It has proved rather 

 uncommon in our dredgings, but it grows abundantly on piles throughout the region. 



Bugula murrayana (Johnston). [PI. xxn, fig. 26, 26a.] 



Johnston 1847, p. 347 (Flustra murrayana). 



Dcsor 1848, p. 66 (Flustra Iruncata). 



Packard 1863 (Flustra murrayana), 1867, p. 273 (Menipea fruticosa). 



Vcrrill and Smith 1874, p. 711. 



Verrill 18793, p. 52, and i87gb, p. 189, and 18790, p. 29 (as B. murrayana and B. murrayana var. fruticosa). 



Whiteaves 1901, p. 93. 



Zoarium dichotomously divided into broad foliose or ribbon-like strips, truncate at tip, or some- 

 times (var. fruticosa Packard) the divisions are narrow and linear. Zooecia multiserial in four to 

 twelve rows, alternating, oblong, truncate above and narrowed below. Aperture reaching nearly to 

 the bottom; an erect spine at each angle above, and a varying number (i to 5) of marginal spines 

 curving over the aperture. Avicularia of two kinds, the smaller ones situated on the front of the cells 

 at the bottom, with the mandible turned upward, the larger ones on the lateral cells only, situated 

 on the outer margin of the aperture, and several times as large as the others; in both the beak is 

 strongly hooked. Ooecia large, wider than the top of the zooccia, subglobose, with radiating striae. 

 Radical fibers long, stout and wrinkled, arising from the marginal cells near the base of the zoarium. 

 Height l /2 to 1^2 inches. The light yellowish or brownish colonies stand up like small frills on the shells 

 and pebbles to which they are attached. 



Very common in the outer waters of the region; Crab Ledge, Great Round Shoal, off Sankaty 

 Head, etc., in 8 to 25 fathoms. Noted by Yerrill off Gay Head in 10 to 20 fathoms. Not taken in 

 Vineyard Sound or Buzzards Bay. 



Bugula avicularia (Linne). [PI. xxi, fig. 27.] 



Linne 1758, p. 809 (Sertularia avicularia). 



Verrill 18793, p. 52, 1879!), p. 189, and 18790, p. 29. 



This species has been recorded by Yerrill from "Long Island Sound to Spitzbergen," but it has 

 not appeared in any of the collections from the Woods Hole region. The species may be recognized 

 by its biserial arrangement of the zooecia, together with the large size of the avicularia, which are 

 elongated and have the long slender beak gently curved to its tip. In our other species of this region 

 the beak is* abruptly decurved near its tip. 



Family MEMBRANIPORID^E Busk, 1854. 



This family has a large representation in the waters of this region. All our species are incrusting, 

 and the majority of them have the aperture widely open. I have followed Waters (1898) in merging 

 Biflustra with Membranipora, so all of our species fall within the limits of one genus. 



Genus MEMBRANIPORA Blainville, 1834. 



KEY TO SPECIES. 



1. Front wall inside of raised margin entirely membranous .2. 



Front wall partly (sometimes very slightly) bridged over by a calcareous lamina 3. 



2 . Ooecia and avicularia absent 4- 



Ooecia and avicularia present e 



4. Entirely devoid of spines, or with very slender erect spinules lacroixii. 



Spines well developed 6 



