OF SOUTIIERX IXDIA. 
19 
arc entirely worn away, or do not appear to have become at all developed. All these 
stages may be seen in one and tlie same colony, as shown in fig. 1, on pi. ii. 
The slitters are clongately ovate, with similarly shaped sub-central, depressed 
apertures. 
When the surface of the colonies has been slightly worn off, the ridges between 
the cells disapjiear, while the impressed lines between them become more distinct. 
At the same time the aperture slightly widens by the fine edges, or laminae, being 
broken away, and assumes either a roundly quadrangular or nearly rounded shape. 
Tlie oral region is, however, ahvays somewhat depressed. 
Localities. — Yermanoor, in yellowish sandy beds, Chokonadapooram and 
Ootacoil, m a pinkish limestone ; very common. 
Formation. — Ai’rialoor group. 
VIII. Genus. — BIFLUSTRA, d'Orhigny, 1851, (see p. 11). 
1. Bifltjstra cingitlata, Stoliczka, PI. II, Fig. 6. 
Bif. ramulis latis, compressis ; cellulis magnis rotmidate stih-hexagonis, in 
.seriehus ohliquis dispositis et stUcis angustis separatis ; apertura magna, late ovata, 
subantica, margine undique elevato circunidata ; fissorihus cellulis paulo minoribus, 
rliombif omnibus atque in dimidio supero margine valde elemito preedit is ; apertura, 
elongate eliptica. 
A very characteristic species, with broadly foliaceous, compressed branches. 
The cells are large, sub-hexagonal, with ovate, somewhat anteriorly placed apertures ; 
each cell is surrounded by an elevated margin and separated from the neighbouring 
ones by narrow grooves. The slitters are somewhat smaller than the other cells, 
diamond-shaped, with a similarly formed aperture, and on the upper half of each 
the margin is very much higher than on the lower one. No ovicells have been 
observed. 
Locality. — Yermanoor, in a yellowish soft sandstone. 
Forma tion. — Arrialoor group . 
2. Family, — SELENABIIJDJE. 
Busk, Crag Polyzoa, Palseonto. Soe., p. 78. 
Colonies more or less orbicular or conoid, composed of a single layer of cells, 
loitli their orifices all on one side only ; partially attached when young, but usually 
quite free lohen adult; cells broadly urceolate, toith a rather large aperture, or 
fustrine, mostly loith loell developed vibracular cells. 
The attachment of the colonies is usually only indicated by the central or 
oldest cell being fixed to a small portion of sbcll or a grain of sand, wliich does 
not in any way interfere with the movements of the whole colony when it is adult. 
( 53 ) 
