The Bryozoa of the Tortugas Islands, Florida. 215 



Genus Holoporella Waters, 1909. 



Holoporella albirostris (Smitt). 



Smitt, 1873, p. 70 (Discopora albirostris). — Busk, 1881, p. 346 (Cellepora albirostris). — 

 Jelly, 1889, p. 45 (references under Cellepora albirostris). — Waters, 1885, 

 p, 304; 1887, p. 68 {Cellepora albirostris); 1909, pp. 159-161 {Holoporella 

 gen. nov.). 

 This species, which is very characteristic of the region, occurs in abun- 

 dance from low water to 15 fathoms. It grows on coral-rocks, corals, shells, 

 and on the firmer sponges. Recorded by Smitt from Florida waters in 25 

 to 35 fathoms. It is readily distinguished from other species of this region 

 by the presence of a towering, pointed white spine situated at one side 

 of the proximal margin of the orifice. Except in the youngest stages the 

 colony has a dark grayish or blackish color, against which the white spines 

 stand out in sharp contrast. A very small avicularium is situated at the 

 base of the spine, large spatulate avicularia are distributed over the colony, 

 and vestigial, minute avicularia are occasionally present at the side of the 

 orifice. 



Waters in 1909 (1. c.) established the genus Holoporella to include, for 

 the most part, those species of the old genus Cellepora in which the sinus 

 is lacking and which have a rounded or straight posterior margin of the 

 orifice, and in which also the opercular muscles are attached near the 

 border. Levinsen (1909, p. 347) erected a new family, Holoporellidae, to 

 include this genus, thus farther removing it from Cellepora. This separa- 

 tion is based on the fact that in Holoporella the operculum is attached, 

 sometimes by hinge teeth, to the lateral margins of the orifice, while in 

 Cellepora the operculum is suspended at the edges of the sinus. Oral spines 

 are often present in Holoporella, but are wanting in Cellepora. Rostra, with 

 avicularia, may be present in both genera. Waters includes the following 

 American species of the Florida region in Holoporella: H. {Discopora) 

 albirostris (Smitt), H. {Lepralia) turrita (Smitt), and H. {Discopora) pertusa 

 (Smitt). Levinsen adds H. {Discopora) advena (Smitt), which apparently 

 completes the list of the described species of this region. 



Holoporella pusilla (Smitt). 



Smitt, 1873, p. 70 {Discopora albirostris forma pusilla). — Busk, 1884, p. 436 {Cellepora 

 pusilla). 



In the "Floridan Bryozoa" Smitt describes this species as a form of 

 his Discopora albirostris, stating that their relationship is " incontestably 

 proved by the very same form of the zooecial aperture." Busk (1. c.) 

 objects to placing pusilla as merely a variety of albirostris, giving it as his 

 opinion that the two seem to him to be quite distinct. Although Busk 

 possessed no material of pusilla, he was evidently correct in forming this 

 opinion. If the single specimen taken by me at the Tortugas is identical, as 

 I believe it to be, with Smitt's pusilla, it differs from albirostris in the entire 

 absence of dark pigment; in the smaller size of the colony, the individual, 

 and the orifice; in the presence of radiating lines of depressions and small 



