GUETTARDIA.— COSCINOPORA. 105 



(figs. 3, 4, 8, 9), as they clearly belong to the same species. The Museum possesses 

 several specimens from Biarritz which correspond very closely with D'Archiac's figures 

 of G. Thiolati from that locality ; and I am unable to find any satisfactory differences 

 to distinguish them from the Chalk specimens of G. stellata, beyond those which may 

 arise from difference of preservation. As a rule, however, they are smaller than the 

 Chalk forms. 



The example figured by Mantell under the name of Ventriculites quadrangularis*, 

 is stated by T. Smith to be a fragment of this species ; but neither Mantell's figure 

 nor description is sufficiently clear for satisfactory recognition. 



Distribution. Grey Chalk : Dover. Lower and Upper Chalk : Boxley, Kent ; 

 Croydon, Shalford, Surrey ; Glynde, Sussex ; South of England (coll. T. Smith). 

 Cretaceous : Biarritz [coll. Pratt). 



GuETTARDiA RADIANS, Hinde, XI. sp. (Plate XXV. fig. 3.) 

 1840-47. Guettardia stellata, Michelin, pars, Icon. Zoopli. pi. 30. f. 1, 2, 5. 



Sponge consisting of a varying number, from 3 to 5 generally, of compressed 

 branches, which spring from a common, slightly inflated, hollow base, supported on 

 a short stem. The branches are from 14 to 24 mm. in width ; the parallel walls are 

 about 2 mm. in thickness, and about the same distance apart ; circular apertures are 

 present on both the lateral margins. The wall-surface appears to be covered with 

 minute canal-apertures similar to those in G. stellata. No spicular structure is 

 present in the specimens. 



I propose this species to include some of the forms included by Michelin under 

 G. stellata, but which differ from those to which I have restricted this term in the 

 fact that instead of forming flanges which open throughout their length into a central 

 cavity, the sponge divides into compressed branches, thus resembling a compound 

 Pleurostoma. 



Distribution. Craie Chloritee : Vaches Noires. Biarritz ? {coll. Pratt). 



Genus COSCINOPORA, Goldfuss, 1826-33. 



COSCINOPORA INFUNDIBULIFORMIS, Goldf. 



1826-33. Coscinopora infmdibuliformis, Goldf. Petref. 1 Th. p. 30, t. 30. f. 10. 



1877. Coscinopora rnfundibuliformis, Zitt. Studien, I Ab. p. 49; Neues Jahrbuch, ]>. 359, 

 t. 2. f. 4. 



1878. Coscinopora in/undibuliformis, Zitt. Handb. der Pal. p. 175, f. 91. 



There are several examples from the Upper Chalk of the south oi England which 

 correspond in form and in the arrangement of the canal-apertures with typical 



* Geology of Sussex, p. 177, t. 15. f. 6. 



