2 G 
the farcimentiferous outline of the autopores is much less marked than in the 
latter. Furthermore, the alignment of the corallites in a chain is more 
continuous and unbroken in the present species than it is in II. Sussmilchi, 
as the mesoporcs do not occur in re-entrant spaces, although the alignment 
in II. ortliopteroides is not so continuous as in II. lithoslrotonoides. 
The reduction of the mesopores to mere slits is not due to infilling, or 
thickening of the tissues, hut is structural ; the proportion of mesopores present 
or absent is about equal, and when these zooids are not present the autopores 
abut against one another, and are only separated by the intervening walls. 
The regular triangular outline of the gonopores, and the frequent 
truncation of one of the angles, are very characteristic features in this 
species. The alignment of the corallite chain margins is more or less regular, 
like those of II. lithosfronoides, and in consequence, those of II. catenularius, 
var. gracilis (Hall), Lambe. 
Loc. and Horizon. — L. Smith’s Station, Portion 98, Ph. Gamboola, 
Co. Wellington ( C . Cullen). 
Collection. — Mining and Geological Museum, Sydney. 
IIalysites Sussmilchi, sp. nor. 
(PI. Ill, Figs. 3 and 4 ; PI. VII, Figs. 1-3.) 
Sp. Char. — Corallum expanding sub-pyriform, the parent corallites 
sub-radiate from a common base, forming colonies up to seven and a half 
inches high hv six inches wide. Fenestrules variable in size, and particularly 
in outline, round, oval, elongate, S-sliaped, dumb-bell shaped, roughly 
polygonal, labyrinthine, or quite irregular, but, as a rule, one axis greatly 
exceeds the other; sizes 3x3 mm., 5x5 mm., 9x2 mm., 10 x 3 mm., 
12 x 5 mm., 15 x 3 mm., and so on, up to 25 mm. in length; margins 
strongly undulate ; walls coarsely and strongly corrugate or ribbed. Epitlieca 
coarsely striate. Corallites long, at least four inches, and then imperfect. 
Corallite chains strongly farcimentiform. Autopores round or round-oval, 
from five to twenty-five in each corallite chain ; length, one to one and a half 
millimetres by one in breadth ; visceral chambers transversely elongate 
(parallelogrammatic) ; tabulae well developed, complete, horizontal, half a 
millimetre apart. Gonopores well developed, triangular, quadrangular, or 
polygonal ; tabulae complete, horizontal, one-third of a millimetre apart ; 
walls of equal thickness to those of the autopores. Mesopores well developed, 
