42 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 43. 



UMBELLTILA MAGNIFLORA Kblliker. 



Umbellulamagniflora Kolliker, Challenger Reports, the Pennatulida, 1880, p. 24. 



Five fine specimens in an excellent state of preservation and all 

 evidently of the same species, afford an interesting study in the 

 variations in measurements of this beautiful Umhellula. The series 

 was arranged with reference to the size of polyps. 



Specimen 

 No. 



Total 

 length. 



Rachisand 

 polyps. 



Polyps. 



Tentacles. 



Number of 

 polyps. 



1 



2 

 3 

 4 

 5 



Cm. 

 51 

 8.3 

 S3 

 54 

 80 



Cm. 

 9.3 

 5.0 

 5.3 

 5.0 

 5.5 



Cm. 

 4.9 

 3.8 

 2.9 

 2.4 

 2.3 



Cm. 

 2.8 

 Absent. 

 1.6 

 1.2 

 1.5 



21 



10 



9 



8 



9 



No. 1 is a distinct pinkish salmon in color, except some of the 

 polyp bodies which are a reddish brown. This color is superficial, 

 however, and is easily rubbed off. 



Nos-. 3, 4, and 5 are almost white, with a slight pinkish cast, tend- 

 ing to a light salmon in the pinnules. 



These measurements seem to show that there is no relation between 

 the a.ge of the colony, as indicated by the number of polyps and the 

 length of the stalk. There seems, however, to be a general relation 

 between the size of the polyps and the number on a colony. 



Aside from being much larger, the polyps of No. 1 are much more 

 fully expanded than those of the other specimens. 



The following additional facts were noted regarding specimen 

 No. 1 : 



There is a distinct swelling above the end bulb, 1.2 cm. in diameter, 

 the least diameter of the stem being 2 mm. The polyps are fully 

 extended and increase from 2.5 mm. in diameter near the distal 

 end to 6 mm. near the base. The polyp walls are smooth and semi- 

 pellucid, the mesenteries showing plainly through them. There 

 are a number of shallow corrugations disposed in an annular manner 

 around the upper part of the body walls. 



There are about 34 pairs of long, filiform pinnules in each tentacle. 



The zooids are very numerous, covering the rachis where not 

 occupied by the polyps. Those on the rachis do not regularly have 

 tentacles and appear to the naked eye as rounded granules. Under 

 magnification they show a central mouth. On the lower part of 

 the stalk they are smaller, but each has a long unbranched tentacle. 

 Although rubbed off in places, they were undoubtedly originally 

 emplanted on all parts of the stalk. 



There were no spicules found in these specimens. 



