HOMCEOSOLEN. 
75 
face; X 10 dia. Fig. Ah, the reverse face of the same specimen; 
X 10 dia. Fig. 4c, the end of the stem from above, showing the 
triangular form of the branch; x 15 dia. D. 1872. 
PI. YI. Fig. 5. The worn base of a five-branched zoarium, also 
Vine’s Osctdipora pleleia. Cambridge Greensand. Jesson Coll. 
Fig. ba, the obverse face of the zoarium ; x 6 dia. Fig. bh, the 
reverse face of the same specimen ; x 6 dia. D. 1880. 
Affixities. 
This species is best known from the fine series of figures given 
by ^ovak, who described it as a new species and made no reference 
to the Hornera carinata of von Reuss. The two names, however, 
appear to be synonymous, for thougli the original figure of carinata 
is sketchy it represents the tumid, well-rounded, and striated 
stems which are so conspicuous in 0. pleheia. 
The kSenonian Bryozoon, identified by d’Orbigny as T. carinata, 
appears to me, however, essentially distinct, and to include forms 
of the two species H. ramulosus and II. gamhlei. 
Pocta {op. cit. p. 7, fig. 3) gives an excellent transverse section 
(X 26 dia.) showing the intimate structure of the species; the 
large zooecia in the lateral processes are ’I mm. in dia., while the 
longitudinal zooecia in the stem are smaller, ranging from *08 down 
to •02 mm. in dia. The stem is strengthened front and back by 
a layer of laminated tissue, which does not appear to have any 
cancelli. The structure is essentially that of the Cyclostomata 
Tubulata, and not of the Cancell ata. 
LIST OF SPECIMENS. 
British. 
D. 1872. Two fragments ; one is the worn base of a young zoarium (on slide). 
Cambridge Greensand. Cambridge. Jesson Coll. Recorded as 
Osculipora pleheia, IS'ovak, by Vine, 1885. Proc. Yorks. Geol. 
Soc. new ser. vol. ix. p. 22 ; and 1889, ihid. vol. xi. p. 270. 
Figd. PI. VI. Figs. 4a-c. 
D. 1880. Four fragments (on slide) ; one is the base of a five-branched zoarium. 
Cambridge Greensand. Cambridge. Jesson Coll. Recorded as 
Osculipora pleheia, Novak, by Vine, 1885. Proc. Yorks. Geol. 
Soc. new ser. vol. ix. p. 22; and 1889, ihid. vol. xi. p. 270. 
Figd. PI. VI. Figs. 5a, h. 
D. 1877. Three fragments of the bases of zoaria (on slide). Cambridge Green- 
sand. Cambridge. Jesson Coll. 
