MUSEUM OF CgMPARATIVE ZOOLOGY. 103 



Variety 5.— PI. I. Figs. 6, 7, 8. 



Base nearly flat, with a small umbo in the centre, hardly marked in most 

 specimens, outline of section somewhat re-entering above, so that the diameter 

 of the calicle is somewhat less than the diameter of the base. Costse equal, 

 flat, thick, and contiguous, separated only by a linear though rather deep 

 furrow, finely granulated, and having a faint granular keel. The pali are 

 thick, and the columella oblong, composed of thick pillars, and well separated 

 from the pali ; the septa are thickened at the outer borders, covered laterally 

 by short thick spines. All the specimens are uniformly white, without pur- 

 plish spots. Moseley's D. magnificus resembles it in outline, but has not the 

 same costee, septa, and columella. I have seen no passages between this form 

 and the others, when adult, but in the young the costoe are thin, and not 

 essentially diff"erent from variety a. 



Depth seems to have no influence on the prevalence of one or the other 

 form. 



In the polyps the outer sphincter when contracted covers the tentacles 

 which are drawn back in the notch between the septa and pali. The oflice of 

 the pali seems to be partly to support the buccal membrane, partly to protect 

 the retracted tentacle. They never support extra tentacles in any of the 

 corals in which I have had the chance to observe the well-preserved polyp. 



Range from 73 to 878 fathoms in .39 stations, off Havana, in Old Bahama 

 Channel, off Santa Cruz, Virgin Gorda, St. Kitts, Montserrat, Guadeloupe, 

 Dominica, Martinique, St. Lucia, St. Vincent, the Grenadines, Grenada, and 

 Barbados. 



Stephanocyathus elegans Segdenza. 



Three fine specimens of this species were obtained, two living and one dead. 

 They agree most with Seguenza's variety subspinosiis. 



The second lobe of the pali, generic character according to Seguenza, resem- 

 bles the parts of the columella, but is well separated from it ; it is not constant, 

 and distinct only in the second or third order. The columella, which is 

 formed of twelve or more blunt prongs, is in younger specimens more diffuse. 

 The septa of the fourth cycle unite through their pali with those of the third, 

 and the latter with the second. The septa cf the fifth cycle are small, and 

 reach only half-way to the centre. 



The polyp has stout tentacles ; in one specimen those of the three first 

 cycles were white, the others dark purple, with white tips ; in the other they 

 were all purple, those of the youngest order least so. They are disposed in 

 several circles, and do not appear to be very retractile. The outer sphincter is 

 not distinctly marked. The buccal membrane is very thin, and in both speci- 

 mens many of the pali had pierced it. 



Eange from 209 to 288 fathoms, in three stations off Barbados. 



