284 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 105 



frontal type (pi. 22, C). Otherwise, in avicularial shape and man- 

 dibular appearance the two types are quite similar or intergrade into 

 each other. The oral avicularium is mounted on the side of the 

 mucro, facing either to the left or to the right, with beak pointing 

 outward (pi. 22,D,F). Sometunes the mucro and beak have a slightly 

 curved tip. The mucro houses the avicularial chamber. The frontal 

 avicularia also are mounted along the side of a smaller umbo. They 

 generally face toward the middle of the zooecium (pi. 22,A) although 

 some variations occur. They may be located anywhere on the frontal 

 but usually are on the proximal half of the zoid, only rarely near the 

 peristome. 



The oral mandible is roughly triangular, gently curved, and has a 

 hooked beak (pi. 22,G,I,J). Its outer border is more chitinized than 

 the central area. The frontal avicularium mandible is similar in 

 appearance. 



Orifice : The orifice is nearly terminal. Its distal peristomial wall 

 is formed in part by the next distal zooecium. The primary orifice 

 is usually obscured or hidden by the peristome and aviculiferous 

 mucro. It is a bit wider than long, smittinoid, with cardeUes and a 

 low broad lyrula (pi. 22,E,L). Its operculum is thin and lightly 

 chitinized. The secondary orifice varies from lepralioid (pi. 22,B) 

 to approximately trifoliate (pi. 22,0). Its anter is hemispherical, 

 its poster is much wider and flatter. The oral avicularium-bearing 

 mucro projects prominently in front of it. The peristome is highest 

 at the sides of the orifice and low at the proximal corners. No spines 

 were seen about the orifice. 



OviCELLis: Salient, nonporous, globose, well calcified, tipped for- 

 ward, partly overhanging the orifice. Some have a shallow oval or al- 

 mond-shaped depression (pi. 22,A,0) near the border. Areolar pores 

 of the next distal zoid sometimes outline the ovicell but do not perforate 

 the ovicell wall. Ovicell surface is granular to beaded, occasionally a 

 bit grooved. Embryos present in ovicells collected from Station 190. 



Distribution and Ecology: The holotype of this species (USNM 

 11289) comes from Station 190; paratypes were taken at Station 44 

 and from Rocks 3 and 7 (locality unknown). Stations 44 (lat. 65° 25' 

 S., long. 101°13' E.) and 190 (Marguerite Bay) are a considerable 

 distance apart. No entire colonies are in the lot, only pieces, the 

 biggest of which is 18 mm. by 24 mm. The piece from Station 44 

 grows on Cellarinella rossi (see p. 260). The three pieces from Station 

 190 are free, foliaceous chips, with polypides and embryos. On back 

 of these colony pieces, but not on the face, grow a calcareous worm 

 tube and various Bryozoa (Ramphonotus inermis, Membraniporella 

 zoid, ancestrula, and an attachment rootlet) as well as sponge spicules. 

 The specimens encrusting Rocks 3 and 7 were removed by calcining. 



