420 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



HOLOPORELI.A TURRITA Smitt, 1873 



Plate 59, figs. 1-5 



1873 Lepralia turrita Smitt, Floridan Bryozoa, pt. 2, Kongl. Svenska 

 Vetenskaps-Akademiens Handlingar, vol. 11, no. 4, p. 65, pi. 11, figs. 

 226-228. 



Description. — The zoarium forms small globular masses attached 

 to algae or more often fixed to nullipores; the color is a beautiful 

 flesh rose. The zooecia are little distinct, orbicular, or hexagonal, 

 little convex, of large dimensions; the frontal is covered over by 5 

 large avicularia, the orifice of which is small and poriform. The 

 latter is often surrounded by a tubular and very salient peristome. 

 The apertura is median; the anter is in the form of a bell and the 

 poster is concave. The ovicell is smooth, small, globular. The 

 interzooecial avicularia ( = zoarial) are relatively small; the orifice 

 is orbicular, small, and traversed by a pivot; the beak is wide and 

 rounded; the mandibular cavity is smooth and shallow. On the 



C 



-Opercula, X85, of Holoporella turrita 

 Smitt, 1873 



A. Ordinary zooecia. B, C. Two forms of salient zooecia. 



zoarial surface there are often large salient zooecia with smooth 

 frontal, arranged in sporadic groups of 2 or 3. 



Measurements. — Aperture of ordinary zooecia = 0.20 mm.; aper- 

 ture of sporadic zooecia = 0.20-0.25; ordinary zooecia = 0.60; spo- 

 radic zooecia = 0.60-0.70; and length of zoarial avicularia, 0.50. 



Variations. — The sporadic zooecia are not formed by all the 

 colonies. On the same colony and without apparent reason the 

 poriform avicularia are sometimes little salient, sometimes very 

 salient (length = 0.20 mm.). The incomplete zooecia are very rare; 

 they engender the sporadic zooecia. 



The opercula of the ordinary zooecia are somewhat transverse, 

 but the opercula of the sporadic zooecia are a little elongated. The 

 muscular attachments are always lateral. The inferior portion is 

 always thicker and granular. The arrangement of the attachments 

 on the opercula is rather variable and changes according to the 

 locality. 



Biology. — All our specimens were living; they were ovicelled 

 February 15-18, 1908 (32-39 meters). They have a beautiful flesh 

 color with the opercula of a deeper shade. This is a true equatorial 

 species; it prefers warm waters and little depths. Here in the 



