108 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



whose expanded base is continuous with that of adjacent zooids. 

 Connection between the zooids of the colony is Iry vascular processes 

 from the posterior end of the body and appears to persist under 

 normal conditions in fully adult zooids. 



Test not thick but tough and opaque, of a brownish color exter- 

 nally, becoming purplish brown about the apertures. In the zooids 

 from station D5174 this purplish color is distributed in about four 

 broad stripes radiating from the branchial aperture and extending 

 some distance back. External surface rather rough, somewhat 

 wrinkled and slightly incrusted with foreign material; internal sur- 

 face with a thin whitish, slightly pearly layer. 



Mantle moderate^ thick, adherent to the test; its muscles fairly 

 well developed but not gathered into conspicuous bands. Individual 

 fibers or slender groups of a few fibers form a network with small 

 more or less rectangular meshes. 



Tentacles about 32 ; of three sizes arranged with some regularity. 



Dorsal tubercle much elongated longitudinally, with a slitlike or 

 long oval orifice. 



Dorsal lamina plain-edged. 



Branchial sac with but two folds on each side separated by rather 

 wide intervals. The grouping of the internal longitudinal vessels 

 does not appear to indicate other rudimentary folds. The branchial 

 sac is not symmetrical, being more expanded and with more numerous 

 internal longitudinal vessels on the right than on the left side. 

 Transverse vessels rather widely spaced, of 2 sizes placed alternately, 

 the smaller crossing the stigmata which are rather long. Internal 

 longitudinal vessels numerous and slender, separated by about three 

 or four stigmata on the intervals between folds. In a large zooid their 

 distribution was found as follows: 



Right side: dorsal 9 (16) 9 (14) 9 ventral. 

 Left side: dorsal 6 (15) 9 (12) 7 ventral. 



In another individual: 



Right side: dorsal 5 (17) 8 (14) 9 central. 

 Left side: dorsal 3 (14) 7 (12) 9 ventral. 



Stomach short and rounded, with 20 to 25 longitudinal plications but 

 no caecum. Intestine of large diameter, but forming a rather small 

 loop. Rectum long. Margin of anus smooth or nearly so. 



Reproductive organs were found only in the specimens from 

 stations D5174 and D5555. These also contain large tailed larve in 

 the peribronchial cavity. Only the ovaries form compact gonads, 

 each gonad consisting of a group of a very few eggs (but one of 

 which appears to become very large at a given time) inclosed in a 

 small sac having a large irregularly lobed opening produced into a 

 papilla or very short oviduct. These female gonads, which average 



