HOM(EOSOLEN. 
95 
PL III. Fig. 5. Obverse face of the base of a zoarium with 
a gonoecium; X 15 dia. Middle Chalk — zone of Micraster cor- 
testudmarium : Chatham. Gamble Coll. D, 4365. 
PI. III. Fig. 6. Obverse face of a fragment with long pinnules; 
X 12 dia. Middle Chalk — zone of Micraster cortestudinarium : 
Chatham. Gamble Coll. D. 4365. 
Affinities. 
The first obvious character shown on d’Orbigny’s figures of this 
species is the occurrence of pores over the reverse surface, as well 
as the apertures on the obverse surfaces ; but the reverse pores are 
only due to the removal of the external surface, and they occur in 
any worn species of Homoeosolen. 
The two essential characters of the species are the raised sinuous 
ridge near the distal ends of the branches on the obverse surface 
and the nature of the sub-branches. They are short, subalternate 
or alternate, and irregular in character. The nearest ally of this 
species is H. gamhlei, which differs by the greater regularity of its 
branching and by having a more ridged reverse surface. In the 
latter respect H. fenestratus agrees with M. ramulosus, but differs 
therefrom by not having the flamboyant arrangement of the 
branching and by having short sub-branches nearly at right angles 
to the main stems. 
LIST OF SPECIMENS. 
British. 
D. 3968. Two fragments of variety with long pinnules, showing obverse and 
reverse faces (on slide). Middle Chalk — zone of Micraater 
cortestudinarium. Chatham. Gamble Coll. Figd. PI. II. 
Figs. 9, 10. 
D. 4365. Three fragments, one with gonoecium (on one slide). Middle Chalk — 
Zone of Micraster cortestudinarium. Chatham. Gamble Coll. 
Figd. PI. III. Figs. 5, 6. 
D. 405. Two fragments (on shde, with a Supercytis stage of another species). 
Middle Chalk — zone of Micraster cortestudinarium. Chatham. 
Gamble Coll. 
D. 676. A branch showing parts of both faces (on slide). Middle Chalk — zone 
of Micraster cortestudinarium. Chatham. Vine Coll., I^o. 80, 
Eecorded as Truncatula suhpinnata. 
D. 3050. An irregular loose zoarium. Upper Chalk. Dover. Bowerhank Coll, 
D. 3055. Branch of a zoarium 12 mm. long partly embedded in flint. Middle 
Chalk — zone of Micraster cortestudinarium. Chatham. Presented 
by William Gamble, Esq., 1889. 
