CORALS AND BRYOZOA. 217 



FiSTULIPORA UNILINEA, n. Sp. 

 PLATE LVII, FIGS. 1,2, 5. 



ZoARiUM sometimes consisting of thin lamellata expansions, incrusting Cyatho- 

 phylloid corals or other objects, but very frequently forming hemispherical 

 or spheroidal masses by the superimposition of successive layers of growth. 

 Cells tubular, cylindrical, rectangular to the surface ; septa wanting. Inter- 

 cellular space vesiculose, vesicles near the base large, irregularly disposed, 

 more regularly superimposed above, but never having the appearance of 

 septate tubuli. When the vesicles are regularly superimposed there 

 are about forty in the space of 5 mm. Cell apertures circular, diameter 

 .33 mm., very closely and irregularly disposed ; on different fronds and 

 under different conditions they vary greatly in appearance ; usually the 

 peristomes are thin, equally elevated, and the apertures surrounded by one 

 series of mesopores ; on other fronds the peristomes are more decidedly 

 elevated and the apertures are a little more distant. Sometimes there is an 

 oblique projection or slight denticulation on the posterior portion of the 

 peristome ; at other times, on portions of a frond, the peristomes are thick- 

 ened, coale.scing with those of adjacent apertures, obliterating the mesopores, 

 which in this condition resemble the polygonal cell apertures of a Ch^tetes. 

 When the frond is well preserved there are frequent spinules on the peri- 

 stomes. Mesopores minute, usually only one series between adjacent aper- 

 tures ; margins elevated a little less than the peristomes, granulose, the 

 granules very frequently obscuring the mesopores. Surface marked by very 

 slightly elevated monticules, the centers of which are usually distant about 

 6 or 7 mm., with a space 1.50 or 2 mm. in diameter, destitute of cell aper- 

 tures and occupied only by mesopores, which are obscured by the prominent 

 granules on their margins ; the adjacent cell apertures radiate from the sterile 

 areas and are larger than the others, having a diameter of .50 mm. 



This species most nearly resembles F. spheroidea, but may be distinguished by 

 the smaller cell apertures, the granulae on the margins of the mesopores, and 

 the presence of monticules : from F. constrida it is distinguished by the some- 



