REPORT ON THE POLYZOA. 
187 
surface smooth and shining, when decorticated sparsely punctured all over. Orifice arched 
with a straight deeply emarginate lower lip. An avicularium with a curved, lanceolate, 
acuminate mandible pointing inwards on either side immediately above the mouth ; in the 
mature cells a slender bridge in front of the deeply depressed mouth, formed by the gradual 
upgrowth of the wall on each side (not of the peristome proper). A very minute suboral 
pore is occasionally formed by the cutting 
away of a portion of the labial fissure. 
Ocecial cells of the same form as the 
zooecial but with a differently shaped oper- 
culum. Avicularian cells numerous, mar- 
ginal, small. 
Habitat. — Station 142, lat. 35° 4' S., 
long. 18° 37' E., 150 fathoms, green sand. 
I have not been able to distinguish the 
ocecial from the zooecial cells in the natural 
condition, but infer that there must be such 
from the presence of the widely different 
form of opercula presented in a decalcified ma 'o^K^a^^c n n^mies a> Zooeoial omnium ; 5, 
preparation. And with reference to this it 
should be noticed that, in some parts, cells may be observed in which there is no indication 
whatever of mouth or orifice of any kind, the front instead rising into a subconical eminence 
upon which a very minute avicularium is placed. Whether these are merely occluded 
zooecial cells or represent ooecia may be doubtful. As regards the peculiar bridge formed in 
front of the mouth, it should be understood that it has nothing to do with the peristome, 
but is formed entirely from an upgrowth of the thickly calcified wall, the mouth remaining 
of its original conformation and with an unaltered peristome at the bottom of a deep pit. 
What may be the perfect habit, size, or mode of attachment of the species cannot be 
ascertained from the fragmentary portions in the Challenger Collection. 
(6) Adeonella distoma \ Busk (woodcuts 56, 57). 
1 Eschar a coscinophora, Reuss, 1 Foss. W. Tertiarb. p. 67, pi. viii. fig. 20. 
,, ,, Id., Bryoz. cles Sept., p. 70, pi. xi. figs. 1-4. 
,, „ Id., Fauna des deutsch. Oberoligocans II. p. 36, pi. xii. fig. 12. 
„ ,, Stoliczka, Sitzungsb. d. k. Akad. Wiss. Wien, Bd. 1. p. 89, pi. ii. fig. 
11, and pi. iii. figs. 1, 2. 
„ „ Manzoni, Brioz. fossil, d. Miocene d Austria ed Unglieria, p. 14, pi. viii. 
fig. 25. 
IPorellina coscinophora, d’Orbigny, Palseont. Franc;., p. 476. 
Lepralia distoma, Busk, Quart. Journ. Micr. Sci., vol. vi. p. 127, pi. xviii. fig. 1. 
Character . — Zoarium composed of long straggling ligulate branches (sometimes 
