HOMCEOSOLElf. 
93 
LIST OF SPECIMENS. 
D. 395. 
D. 3958. 
D. 3959. 
D. 689. 
D. 4088. 
D. 4087. 
Two brandies of a zoarium, with obverse side broad and uniformly 
covered with very numerous crowded small apertures (on slide). 
Middle Chalk — zone of Micr aster cor test udinarium. Chatham. 
Gamble Coll. Purchased. Labelled Truncatula tetragona. Figd. 
PL III. Fig. 1. 
A complete branched zoarium, ivith large ovoid gouoecium a little 
more than 1 mm. long. It is 4 mm. high and 7 mm. wide. Middle 
Chalk — zone of Micraster cortestudinarium. Chatham. Gamble 
CoU. 
Three fragments (on slide). Middle Chalk — zone of Micraster 
cortestudinarium. Chatham. Gamble Coll. Figd. PI. II. 
Figs. 7«, h. One of the fragments has the reverse surface marked 
by oblique rows of depressions. 
One of two specimens on this slide is a very young zoarium of this 
species. Middle Chalk — zone of Micraster cortestudinarium. 
Chatham. Vine Coll. Figd. PI. II. Figs. h. Both specimens 
on this slide are labelled Semicytis francqana. The second specimen 
is a very young base of a Homxosolen, sp. indet. 
Two zoaria in flints. One includes the base, Avhich is 2’5 mm. in 
diameter ; the height is 10 mm. and the diameter of the branches is 
1*5 mm. ; part of it shows both obverse and reverse surfaces. 
Middle Chalk — zone of Micraster cortestudinarium. Chatham. 
Gamble Coll., No. 7. Identified as Homoeosolen alternatus. 
The base of a young zoarium 5 mm. high, with a flat base 2 mm. in 
diameter; the branches are 1mm. in diameter. Middle Chalk — 
zone of 3Iicraster cortestudinarium. Chatham. Gamble ColL 
Identified as Truncatula alternata. 
9. Homoeosolen fenestratus (d’Orbigny), 1854. 
Synonymy. 
Semicytis fenestrata, d’Orbigny, 1854. Bry. Cret. p. 1050, pi. 795, figs. 8-11. 
,, ,, Pergens, 1889. Eev. p. 386. 
,, ,, Gamble, 1896. Cat. Bry. Chatham, p. 6. 
? ,, ,, Canu, 1897. Bry. St. Cal.: Bull. Soc. geol. France, 
ser. 3, vol. xxv. p. 749. 
Truncatula subpinnata, pars, Vine, 1893. Compl. Eep. ; Eep. Brit. Assoc. 
1892, p. 334. 
Diagnosis. 
Zoarium of branches which divide dichotomously, and in which 
the lateral processes are short, alternate, or sub alternate.. 
The branching is loose and open. 
The reverse side of the branches is marked by from six to eight 
longitudinal ribs, between which in worn specimens are large,, 
distant pores. 
