116 
DESMEPOKID^. 
Dimensions. 
D. 7282. 
PI. IV. Fig. 1. 
Diameter of zoarium 
Length of branches 
Maximum diameter 
Length of lateral processes 
Length of the series of apertures 
Width of the series of apertures 
Number of apertures in each group 
Distance of central lines of adjacent lateral 
processes 
17 mm. 
8 „ 
1-0 ,, 
about *6 ,, 
1 „ 
’•I M 
10 - 1 .) ,, 
•8 „ 
Disteibution. 
Upper Chalk : Beachy Head ; Dover ; Burham, Kent ; Sussex. 
Middle Chalk — Zone of Micraster corteatudinarium : Chatham ; Rochester. 
Lower Chalk — Zone of Holaster planus : Dover. 
Figuees. 
PI. IV. Fig. la. The zoarium of the type-specimen ; natural 
size. Fig. \h, part of one branch; X 7 dia. Middle Chalk: 
Kochester. J. Simmonds Coll. D. 7282. 
Affinities. 
This form of Besmepora is fairly common in the Kentish Chalk. 
The species is characterized by its small simple zoarium with 
usually four or five simple branches. Its nearest ally is 
B. hlacJcmorei, with which it agrees in the idmoniiform arrange- 
ment of the apertures ; but in B. pinnigera the apertures are 
in longer and more regular horizontal series, and the lateral 
processes are separated by wider spaces. 
The biserial lateral apertures suggest a comparison with the genus 
Bituligera, which is, however, an Idmonid, having no cancellate 
interspaces between the groups of apertures. 
LIST OF SPECIMENS. 
D. 7282. The type, a cross-shaped specimen on flint. Middle Chalk. Rochester. 
J. Simmonds Coll. Figd. PI: IV. Fig. 1. 
D. 409. A single branch (on slide). Middle Chalk — zone of Micraster cor- 
testudinarium. Chatham. Gamble Coll. 
D. 415. Two branches (on slide). Middle Chalk — zone of Micraster cor- 
testudinarium. Chatham. Gamble Coll. 
D. 710. A fragment of a branch (on slide). Middle Chalk — zone of Micraster 
cortestudinarium. Chatham. Vine Coll., No. 68«. 
D. 711. Two fragments (on slide). Middle Chalk — zone of Micraster cor^ 
testudinariiim. Chatham. Vine Coll. 
