The Bryozoa of the Tortugas Islands, Florida. 199 



to the ooecia, all appear to me to be identical. Levinsen (see above) has 

 recently made this species the type of a new genus, Trypostega, characterized 

 especially by having the ooecia covered by dwarf zooecia with scattered 

 pores and a minute orifice. 



This species is widely distributed, but on the American coast is known 

 only from the Florida region. Levinsen (p. 281) included Gabb and Horn's 

 and Smitt's records for Lepralia inornata, but failed to include Smitt's 

 Gemellipora glabra forma striatula as a synonym. Smitt (pp. 61-62) sepa- 

 rated the species on the following ground: "The most characteristic differ- 

 ence, which has caused us to place them in different families, depends on 

 the shape of the zooecial aperture," and his figures show some differences, but 

 these may be accounted for by variation. In a single colony in my posses- 

 sion the variation is as great as that shown by Smitt's two specimens. 



Gexus Adeona Busk, 1884. 



Adeona violacea (Johnston). 



Johnston, 1847, p. 325 {Lepralia violacea) . — (?) Reuss, 1847, p. 85 {Cellepora heckeli). — 

 Smitt, 1873, p. 30 {Porina violacea and Porina plagiopora Busk). — Jelly, 

 1889, p. 184 (Aficroporella heckeli), synonymy. — Verrill, 1901, p. 54 (Porina 

 plagiopora). — Norman, 1909, p. 296 (Reptadeonella violacea). — Levinsen, 

 1909, p. 283, discusses genus and species. 



Taken from 5 to 18 fathoms. Both the typical form and the nominal 

 variety plagiopora (Busk) occur and in some colonies the avicularia are 

 intermediate in position between that of violacea and plagiopora. Occa- 

 sionally the characters of both "varieties," together with intermediate con- 

 ditions, may be observed in the same colony. The usual color is purple, 

 varying to nearly black, or through pale bluish to white. 



Smitt recorded the species "from the depth of 35 fathoms W. off Tortu- 

 gas" (Porina violacea), and "at a depth of 60 fathoms W. off Tortugas" 

 {Porina plagiopora), and Verrill has noted the form plagiopora at Bermuda. 

 Otherwise the species has not been recorded from American waters. 



Levinsen (1909, p. 282) has returned to the use of Busk's family Ade- 

 onidfe, thus again breaking up the arrangement established by Hincks in his 

 family Microporellidae. The latter family was based on the presence of a 

 frontal pore (ascopore) as the principal character; but, as Levinsen has 

 shown, this brought together a number of forms which are separated by 

 more fundamental characters. 



Genus Bracebridgia MacGillivary, 1886. 



Bracebridgia subsulcata (Smitt). 



Smitt, 1873, p. 28 (Porina subsulcata). — Verrill, 1901, p. 54 {Porina subsulcata). — 

 Hincks, 1880a, p. 76 {Microporella stibsulcata). 



Abundant from 10 to 12 fathoms. Branching colonies reach a height 



of 2 inches or more. The color in life varies from yellowish pink to orange; 



when dead, white. Smitt recorded the species from 10 to 48 fathoms and 



a dead specimen from 471 fathoms. Verrill has recorded it from Bermuda, 



but otherwise it is known only from the Florida region. 



