TheBryozoa of the Tortugas Islands, Florida. 



203 



One colony 0.5 inch high, composed of 24 internodes, taken at 10 fathoms 

 on a sponge bed between Loggerhead and Garden Keys, Tortugas. 



Fig. 13- — Arhorella dichotoma n. sp. Portion of colony, showing mode of growth. 

 Fig. 14. — The same, showing details. 

 Fig. is.— The same, operculum. 



Genus Tubucellaria d'Orbigny, 1850-52. 

 Tubucellaria cereoides (Solander). 



SoLANDER, 1786, p. 26 {Cellaria cereoides). — Waters, 1907, p. 129. — Levinsen, 1909, 

 P- 305- 



One small colony about an inch in height was taken at a depth of 15 

 fathoms. This species has not before been taken on the American side of 

 the Atlantic. 



Waters makes T. opuntioides Pallas a synonym of cereoides, but Levinsen 

 believes that they should be kept separate. This difference of opinion, 

 which has existed since the discovery of the form, does not seem likely to 

 reach a settlement soon. The single specimen taken by me at the Tortugas 

 is not sufficient to decide the point. It agrees closely with specimens of 

 cereoides of the same size taken at Naples, but cereoides has hitherto been 

 limited to the Mediterranean by those who separate the species, while 

 Atlantic specimens are considered to be opuntioides. 



Genus Escharella (part) Gray, 1848. 



Escharella costifera n. sp. (Fig. 16.) 



Zooecia of moderate size, rather regularly ovoid in form, evenly swollen, 

 nearly hyaline. Around the margin is a row of rather large pores, between 



