116 PEOCEEDIFGS OF THE NATIONAL MUSEUM vol.72 



Biology. — The most fruitful species are not necessarily the most 

 common. Smittina ecJiinata is a good example of this, for only a few 

 specimens have been found. The innumerable larvae are probably 

 an easy prey for many marine organisms. 



Occurrence. — Cedar Keys, Fla. 



Cotypes. —Csit. No. 7596, U.S.N.M. 



SMITTINA LABELLUM, new species 



Plate 17, Figures 6-10; text Figures 22 a, g, h 



Description. — The zoarium encrusts small fragments of shells and 

 corals and often consists of two superposed lamellae. The zooecia 

 are distinct, separated by a salient thread, somewhat elongated, 

 irregularly rectangular; the frontal is finely granular, bordered by 

 scattered areolar pores, convex, formed of a tremocyst with very 

 small pores (visible only under strong magnification) . The apertura 

 is small, suborbicular; a small lyrule and two minute cardelles are 

 placed at the bottom of the peristomie; the peristome is thin, very 

 salient, and bears two distal spines, two large lateral notched lips, 

 and a proximal indentation forming a pseudorimule. The ovicell is 

 large, globular, not as broad as the zooecia, adorned with a frontal 

 area, finely granular. The frontal of the zooecia bears avicularia of 

 variable size, oriented diversely with semicircular or spathulate 

 mandibles. 



Measurements, — Aperturai , „ * " ' 



^ Ua = 0.10mm, 



fi:0 = 0.60-0.80 mm. 



Zooecium , n i^n n an ^ 



U2;== 0.50-0.60 mm. 

 Diameter of the ovicell = 0.35 mm. 

 Length of the large avicularia = 0.35 mm. 

 Fana^-ioTis .^Irregularity is the rule here, for no zooecium resembles 

 its neighbor. The development of the aperturai lips is very incon- 

 stant; they are very large in the protected portions; the exposed 

 portions of the colony are deprived of them, but the peristome always 

 exhibits two indentations — a proximal one in the pseudorimule and 

 a distal one for the two spines. Certain zooecia have no avicularia; 

 others have two or three; their form, position, orientation, and size 

 are difficult of accurate description. Often a small triangular 

 avicularium is adjacent to one of the peristomial lips; it is not 

 clearly visible because of its position perpendicular to the zooecial 

 plane. 



Exteriorily the frontal does not appear perforated, and this species 

 could be placed in the genus Smittina as we have defined it. How- 

 ever, in a special preparation it appears perforated by very small 

 tremopores when they are examined at a suitable magnification 



