. 



DIASTOPORA. 131 



DIAGNOSIS : 



Zoarium unilaminate, growing in irregular tubes, which may 

 branch repeatedly or open to funnel-shaped expansions. 



ZooBcia usually visible throughout, the zooecia being long and 

 the apertures usually distant. The peristomes (in well-preserved 

 specimens) are highly raised, and irregular in distribution, though 

 occasionally there is a tendency towards a quincuncial system. 

 Zooecia regularly cylindrical. 



Formula. p, c, I, r = 3, 0, 2, iO. 



DISTRIBUTION. 



BRITISH : 



Inferior Oolite : near Leckhampton ; Postlip ; Stroud (fide "Witchell) . 



FOREIGN : 



Bathonian : Ranville ; Lebisey, Calvados. Braun Jura : Balin. 

 Bajocian: Plappeville (fide Friren). 



Description of Figure. PL VII. Fig. 4. Part of a funnel- 

 shaped end of a zoarium, x 17 dia. Inferior Oolite : near 

 Leckhampton. Brodie Coll. D. 2194. 



Affinities. The zocecia of this species are much like those of 

 D. foliacea, but differ in being slightly shorter, and having the 

 peristomes raised more highly. Moreover, the zoarium is uni- 

 laminate instead of consisting of two layers of zooacia. The 

 irregularity of the distribution of the apertures distinguishes it 

 from D. davidsoni, and the wide distance between these from 

 D. michelini. 



The main difficulty in this species is whether D. waltoni, Haime, 

 is to be included within it. Some specimens in the British 

 Museum (such as 60238) have the peristomes in places crowded 

 and regular, and pass into the waltoni form ; elsewhere, on the 

 same zoarium, they are distant and irregular, and thus are on 

 the lamourouxi type. I have therefore felt bound to merge the 

 species. 



The nearest Cretaceous ally of this species is D. tululus, D'Orb. 1 



Pal. fran9. Terr..cret. t. v. 1852, p. 829, pi. Dcxli. figs. 9, 10. 



