374 PROF. S. H. REYNOLDS AND DR. A. VAUGHAN ON [Aug. I9II, 



the South- Western Province did C. cornucopia; ever attain the large 

 size or abundance that makes this species so important an index of 

 Z„-C 1 throughout the Belgian Province. Dr. Sale'e records the 

 species from Z x (Calcaire de Landelies), where it is not common. 



Caninia patula Mich. (PI. XXX, figs. 5 a-6 b & text-fig. 11.) 



H. Michelin, ' Iconogr. Zooph.' 1840-47, p. 255 & pi. lix, fig. 4. 



L. G. De Koninck, ' Nouvelles Eecberches ' p. 87 & pi. viii, fig. 2 



(Zaphrentis patulci). 

 A. Salee, ' Le Genre Caninia ' Brussels 1910, p. 39 & pis. vi-viii. 



Externally, our specimens accord best with Michelin's figure, 

 except that minor septa are not visible within the calyx as in his 

 type-figure. In this respect, L. G.de Koninck's figured calyx exactly 

 resembles the few specimens that I have been able to collect with 

 well-presetwed calices. Since Dr. Salee, of Louvain University, has 

 given so detailed a description of this species, and has illustrated it 

 by such a wealth of figures, there will be no need to do more than 

 note a few peculiarities of the Burrington specimens. 



This species is characterized by its fossula, wide vesicular ring, 

 and septa continuous to the walls (so that no peripheral zone of 

 large vesicles is developed). The septa are, at least partly, thickened 

 by stereoplasm ; this thickening affects all the septa in the young 

 (see PL XXX, fig. 5 a), the two cardinal quadrants only (see fig. 6 a), 

 or is limited to a lining of the fossula (see fig. 5 6). In a region of 

 thickened septa there is an inner wall, formed of thickened arcs 

 stretching from septum to septum ; this is usually absent on the 

 counter-fossular side. 



There are at Burrington two forms or varieties, which differ 

 only in degree ; they may be defined as widely and closely septate 

 respectively. The widely-septate form is the abundant one, and is 

 represented in PI. XXX, figs. 5 a & 5 6. Pig. 5 a shows the young 

 stage, in which vesicles are undeveloped, the septa are thickened 

 throughout, and the counter- septum is elongated. Pig. 5 b is an 

 adult, in which stereoplasm is practically absent, and the vesicular 

 ring is remarkably Cyathophylloid. It is worthy of note that 

 vesicles first form on the counter-side, so that the ring is much 

 wider on this side (see text-fig. 11, p. 375). 



Minor septa are undeveloped, either in this or in the closely- 

 septate variety, and herein lies the main difference from all the 

 specimens figured by Salee ; it may be that this difference is 

 mutational. 



Figs. 6 a & 6 6 represent the closely-septate form, which is chiefly 

 remarkable for a curious flexure of the tabulae ; this peculiarity is 

 indeed met with in the widely-septate form also, but is there less 

 common. A contoured plan of such a tabula is represented in text- 

 fig. 11 (p. 375), from which the general character is obvious : — A 

 narrow, flat-bottomed fossular valley is bounded laterally by almost 

 vertical walls and behind by a steep slope ; having ascended this 

 slope we find ourselves on a broad, flat plane. Proceeding towards 

 the north across this plane, we encounter a second steep bank that 



