CCENOSMILIA ARBUSCULA. 39 



greater diameter 18 mm. One dead specimen dredged in 40 fathoms on the 

 coast of Brazil, in lat. 11° 49' S. 



The only Flabellum described from the South Atlantic is F. Thouarsii 

 M.-Edw. & H., from the Falkland Islands, which has the costte much less 

 developed. 



RHIZOTROCHUS M.-Edw. & H. 

 Rhizotrochus tulipa n. sp. 



PL VI. jigs, is, 10. 



Corallum conical, pedunculated, costse barely convex; calicle subelliptical, 

 fossa deep ; septa thin, somewhat exsert, with very small tubercles in lines, 

 the primaries and secondaries uniting deep down to form a false columella. 

 The color of the wall is white, septa and cost* a reddish-brown. 



This species is closely allied to Mhisotrochus fragiUs, but differs from it by 

 its exsert septa, which in the latter never reach over the wall. It is also less 

 open, and the septa are thinner and smoother. The root processes are the 

 same. Mhizotrockus fragilis is generally white, rarely colored, and uniformly 

 thin. 



Off Barbados in 100 fathoms. 



Family TROCHOSMILIM] M.-Edw. & H. 



CCENOSMILIA, n. g. 



This genus is formed to receive the Parasmilite propagating by gemma- 

 tion, and thus becoming compound. Single corallites are typical Parasmiliae. 

 I follow herein the example of Milne-Edwards and Haime, though on a 

 former occasion I have departed from it. 



Coenosmilia arbuscula n. sp. 



PI VII. fig. l. 



Corallum forming rather irregular clusters, though the rule appears to be 

 that two corallites grow from the wall of the parent on opposite sides at a 

 very open angle. The simple corallites are regularly conical. Costa) better 



