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THE VOYAGE OE H.M.S. CHALLENGER. 
contiguous. Orifice elliptical from side to side, or semiorbicular or suborbicular. Peris- 
tome sometimes subtubular, sometimes deeply immersed. A small circular immersed 
avicularium on each side of the orifice, sometimes wanting, or replaced by a short, hollow, 
spinous process. Ooecia, when present, deeply imbedded in the superjacent zooecium. A 
raised ridge or keel on the middle of the front, the upper pointed termination of which 
constitutes a more or less prominent mucro in front of the orifice. 
§ a. articulates. 
(1) Bifaxaria submucronata, n. sp. (PI. XIII. fig. 1). 
Character. — Zoarium candelabriform, 1 to 2 inches high. Zooecia subcarinate in front. 
Orifice horizontal, wide transversely, lower or anterior border submucronate. Surface 
sparsely punctured in vertical rows. One or two raised lines down the sides. Avicularia 
small, cup-shaped, circular ; mandible semicircular. 
Habitat. — Station 122, lat. 9° 5' S., long. 34° 50' W., 350 fathoms, red mud. 
(2) Bifaxaria Icevis, n. sp. (PL XIII. fig. 2). 
Antipathes humilis, Agassiz and Pourtales, Hassl. Exped., 1874, p. 8, pi. ix. fig. 9. 
Character. — Zoarium candelabriform, 1 to 2 inches wide. Zooecia completely im- 
mersed but very convex, square or flattened in front with an acute keel, obscurely punc- 
tured. Orifice small, semicircular and slightly sinuate in front. Avicularia small, circular 
or oval, mandible semicircular, completely immersed some distance from the orifice and on 
the same level. Ooecia inconspicuous. 
Habitat. — Station 214, lat. 4° 33' N., long. 127° 6' E., 500 fathoms, blue mud. 
§ /3. inarticulate^. 
(3) Bifaxaria corrugata, n. sp. (PI. XIII. fig. 3, and PI. XXIV. fig. G). 
Character. — Zoarium continuous ; branched bifariously, branches alternate, equi- 
distant, straight, short. Zooecia from 0"‘02 to 0"’03 long, ventricose. Surface strongly 
wrinkled, with a slender keel in front, and finely perforated only on the front. Orifice 
transverse, upper border projecting, lower broad with a pointed hook (when perfect) on 
each side and a smaller one in the middle (being the termination of the keel). A small 
circular avicularium at each angle of the orifice, and occasionally a large one projecting in 
the form of a conical papilla from the side of a zooecium (PI. XXIV. fig. G). 
Habitat. — Station 122, lat. 9° o' S., long. 34° 50' W., 350 fathoms, red mud. 
