712 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



The type was secured by the Challenger, Station 147, South Sea, 

 east of Kerguelen Island, 1,000 fathoms. 



UMBELLULA LOMA, new species. 



Plate LXXXVII, fig. 9. 



Total length of colony 20 cm. Terminal bulb and swelling con- 

 fluent. 'Stem quadrangular in section, in places greatly flattened; 

 greatest diameter, 2.5 mm. to 4 mm.; least diameter below rachis, 1 

 mm. The axis ends in the base of the central polyp. The stem 

 passes insensibly into the rachis, and the latter gradually broadens 

 from proximal to distal ends, where it is somewhat flattened. 



Polyps, in full-grown specimens, 10 in number, the arrangement 

 being such that 9 surround a "central one. Polyp body 10 mm. long, 

 tentacles 13 mm. The basal part of pol3rps is swollen, and its walls 

 are both longitudinally and transversely corrugated. 



The zooids cover the exposed portion of the rachis and are scat- 

 tered over the stem as far as the proximal portion of the swelling, 

 but with a tendency toward leaving a few bare longitudinal lined. 

 The V-shaped bare spaces between the polj^p bases, so characteristic 

 of UmbeUula magnijiora, are not found in this species. The zooids are 

 usually without tentacles, but a few at the bases of the polyps have a 

 single tentacle, while a few others have two. A small patch of 5 

 zooids on the dorsal surface between the polyps are entirely without 

 tentacles, as are those on the stem. The zooids also invade the ven- 

 tral walls of the polyps. 



There are a few very minute, irregular spicules on the end bulb, 

 but they appear to be lacking elsewhere. 



Color. — Fresh specimens; polyps deep umber brown, tentacles 

 somewhat lighter; stem much lighter brown, but with dark spots on 

 end bulb and swelling. 



A cross section of the lower part of the rachis shows the central 

 quadrangular axis and the four longitudinal canals, one being as large 

 as all of the others put together. The canals are divided by longi- 

 tudinal partitions, and the whole system is surrounded by a mem- 

 branous envelope. Outside of this are a number of radiating parti- 

 tions, passing to the outer covering of the stem, and also the tubelike 

 bodies of the zooids, which are continuous with the external portion 

 of the zooids. The mesenteries and mesenterial filaments can be 

 plainly seen. 



Locality. — Near San Clemente Island. Taken at a depth of 330 

 fathoms, by the Loma, a little vessel owned by the Marine Biological 

 Association, of San Diego. The name is given in honor of this exceed- 

 ingly efficient little craft, which has since been wrecked on the point 

 which bears the same name. 



