1889.] NATURAL SCIENCES OF PHILADELPHIA. 117 



7. Mammillifera tuberculata (Gray) (PI. VII, figs. 5 and 6.) 



Synon. — Isaurus tuberculatus — J. E. Gray. 1828. 



Zoanthus tuberculatus — Duchassaing and Michelotti. 1860. 

 Antinedia tuberculatus — Duchassaing and Michelotti. 1866. 

 Zoanthus (Monanthus) tuberculatus — Andres. 1883. 

 Autinedla Duchassaingi — Andres. 1883. 

 This form was first described by J. E. Gray, 1 from specimens in the 

 British Museum, whose locality was unknown. He adopted for the 

 genus Savigny's name Isaurus. In 1860, Duchassaing and Miche- 

 lotti rediscovered it, and, though apparently unacquainted with the 

 earlier description of Gray, applied to it the same specific name, but 

 placed it in the genus Zoanthus on account of the absence of sandy 

 incrustations on the column walls. In their second paper these 

 authors placing importance on the tuberculation of the column 

 walls erected for its reception the genus Antinedia. Andres in his 

 most useful monograph has assumed that the form described by 

 Gray is different from that which Duchassaing and Michelotti ob- 

 tained at St. Thomas and Guadeloupe, relying probably on the dis- 

 crepancies between the poor figures given by the latter authors and 

 the more correct one which Gray has given. He consequently re- 

 tains the specific term tuberculatus for Gray's form, proposing for 

 Duchassaing and Michelotti's the name Duchassaingi. There is 

 little room for doubt, however, that the two forms are identical : my 

 observations have shown that the species is to be referred to the 

 genus Mammillifera as defined by Erdmann. 



The specimens from the Bermudas were either solitary, attached 

 to apiece of rock by a base only very slightly expanded, or else were 

 grouped together in twos or threes in which case they were united by 

 a slightly-developed, flat or slightly-tubular coenenchyme. In none 

 had the coenenchyme any such tubular or stolon-like form as is 

 shown in the figure given by Duchassaing and Michelotti. Judging 

 from the specimens I studied, the tendency to form a coenenchyme 

 is slight. 



The polyps (PI. VII, fig. 5) vary in height from r3-2'7 cm. ; their 

 diameter being about 0'7-0 - 9 cm. The column is marked by six or 

 eight distinct annular grooves, and by from twenty to twenty-five 

 longitudinal ones. In the lower part of the column the ridges formed 

 by these longitudinal grooves are entire, but higher up they begin 

 to be divided into a series of tubercles, a row of these corresponding 



1 y. E. Gray — Spicilegia Zoolo^icn. London. 1828. 



