PEOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 195 



the type of Biscopora. Hincks attributed the name to Fleming, who 

 used it in a different sense, and, apparently overlooking the fact that the 

 name originated with Lamarck, rejected it for the original gronp. 



Biscopora, as I propose to restrict it, is characterized by having both 

 median and lateral avicularia, with the former (or both) oiieu raised on a 

 prominence in front of the zooecial aperture. B. Sl-enei, with its Lepra- 

 lian form described as L. crassispina by Stimpson, is the only known 

 New England si)ecies. 



Escharoides Edw., in Lam., 1835; Gray (restr.), 1848, (noii Smitt). 

 Mucronella {pars) Hincks, 1879, 

 Type E. coccinea (Abildg.), as defined by Smitt,= jB. Feachii (Johnston). 



This group includes those species of Biscoporidcc having a prominent 

 median denticle, but without avicularia. The zooecial aperture is usually 

 somewhat raised, and is often armed with marginal spines. As E. 

 coccinea was one of the species originally included by Milne Edwards, 

 Gray's restriction was correctly made, and should be adopted. 



The typical species, with several varieties, abounds on our coast. 



Mucronella Hincks (restricted), Ann. & Mag., iii, p. 162, 1879. 



Discopora {pars) Smitt, Skandinaviens Hafs-Bryozoer, p. 25, 18G8. 



Characterized by having lateral avicularia on one or both sides of the 

 zofficial aperture, but without the median avicularium. Median denti- 

 cle of various forms, often small. Apertures armed or unarmed with 

 spines. Growth various, most often encrusting, foliaceous, or lichen- 

 like, sometimes forming thick crusts composed of many layers. Our 

 species are as follows : 



Mucronella appensa (Hassal) Yerrill. 



Mucronella pavonella (Alder) Hincks. 



Mucronella nitida Yerrill = Biscopora nit i da V., 1875. 



Mucronella Jacotini (Aud.) V. = EscJiarella Jacotini Smitt. 



Mucronella scabra (Fabr.) V. = Biscopora scahra Smitt. 



M. scabra, var. lahiata (Stimj).) = Lepralia labiata Stimp. 



Mucronella ovata (Smitt) Y. = B. scabra, var. ovata Smitt. 



Mucronella nitida A-'errill. 



Discopora nitida Verrill, Amer. Journ. Sci., ix, p. 415, pi. Tii, fig. 3, 1875. 



This species is very abundant in Yiueyard - Sound and Long Island 

 Sound. Although it is an encrusting species, when young often forming 

 small, thin, radiating patches, when old it forms thick, irregular, cellular 

 crusts, composed of numerous layers of cells. Some of these finally 

 become large, subglobular masses, with an uneven surface, sometimes 

 two inches or more in diameter. The color, when recently dried, is 

 usually bright greenish yellow, sometimes brownish. The younger cells 

 have the walls of both ocecia and zooecia uniformly perforated ; when 

 older, the bounding walls become raised ; a marginal row of conspicuous 

 pores remains, while those over the front mostly disappear, or are 

 obscured by granules; the pores of the globose ooecia also mostly dis- 



