AST. 14 FOSSIL AND EECENT BRYOZOA — CANU AND BASSLBR 111 



Tir ^ A i |^a = 0.08 mm. 



Measurements. — Aperturei , r^ ^r^ ^ ■, . 



^ Ua = 0.10-0.14 mm. 



ry . Ji3 = 0.50 mm. 

 Zooeciai , _ „„ 



I ^2 = 0.32 mm. 



The zooecial width frequently attains 0.40 mm. and there are two 



avicularia symmetrically arranged. 



Biology. — Our specimens encrust nullipores, shells, bryozoa, and 



corals. They were almost all living and in reproduction or fixation. 



One time only have we seen the ectocyst slightly pigmented with 



green. 



The period of reproduction appears very long, but we have not 



yet enough data concerning it. Moreover, this species is quite 



cosmopolitan and the notes published on it are so numerous that 



its biology could be learned. 



Occurrence. — Fowey Light, 15 miles south of Miami, Fla.; 40 fms. 



Albatross Station D. 2405, Gulf of Mexico; 28° 45' 



00" N.; 85° 02' 00" W.; 30 fms.; gray sand, broken 



coral. 



Albatross Station D. 2639, Straits of Florida; 25° 04' 



50" N.; 80° 15' 10" W.; 56 fms.; coral sand. 



Tortugas, 8-29 meters (Osburn); Florida, 11-97 



meters (Smitt). 



MICROPORELLA AMPLA, new species 



Plate 12, Figures 8-10; text Figure 206, c 



Description. — The zoarium encrusts nullipores. The zooecia are 

 distinct, separated by a deep furrow, little elongated, hexagonal, 

 very broad and large; the frontal is convex and finely granular; the 

 ascopore is small, round, marginated. The aperture is small, semi- 

 elHptical; the peristome is little salient and bears five or six spines. 

 The ovicell is small, globular, fringed around the orifice. The avicu- 

 laria are arranged symmetrically on each side of the aperture; they 

 are small, triangular; their mandible is directed upward and toward 

 the median axis of the distal zooecium. 



,, ^ A X \Tia = Q.10 mm. 



Measurements. — Apertures , ^ ,^ 



^ I Za = 0.12 mm. 



[i2 = 0.70-0.74 mm. 



Zooeciai -, _ _„ 



I Z0 = O.5O mm. 



This species is very well characterized by its large dimensions and 

 its small avicularia. The variations in width on the same colony 

 are extraordinary, as may be noted on our figures. The colony 

 measured 6 square centimeters of surface. It was in reproduction. 

 The operculum is bordered by a thick sclerite. 



Occurrence. — Albatross Station D. 2152, 2}^ miles northwest of 

 Habana Light; 387 fms.; coral. 



Holotype.—Ca^t. No. 7557, U.S.N.M. 



