'24 



The measurements of eight of the specimens are as 

 follows : — 



I. Number of Specimen 

 II- ,, Dredging 



III. Length of Calicle. . 



IV. Breadth of do. . . 



V. Height of do. .. 



VI. Length of perpen- 

 dicular from base of 

 pedicle to line join- 

 ing ends of calicle 



VII. Septa fusing by 

 trabeculae . . 



VIII. Total Septa 



5 



13-5 



6 



10 



16 



5« 



The measurements in lines VI. and III. taken together give 

 the angle, which the wings form with one another. 



By comparison with Lesson's figure it will be seen that 

 Nos. I and 2 are almost absolutely similar in shape. Dana 

 figures two specimens, one with basal angle approaching two 

 right angles, and a second resembling No. 3, i and 2 being 

 intermediate. F. distinctuin Ed. and H. differs in having 

 cycles I. -III. equal in size, whereas F. pavomnum has cycles 

 I. -IV. equal ; the fusion of the septa by trabeculae is presumably 

 the same in both cases. The septa of cycles III. and IV. can 

 be easily distinguished in No. 2 and in Nos. 4 7 are very 

 distinct. Yet at the same time cycles I. to IV. are " sensible- 

 ment egales." In No. 3 the distinction is much more pro- 

 nounced and " les trois premiers cycles seulement sont egaux 

 entre eux." Indeed, there is no difference between Edwards 

 and Haime's two species. So far as Duncan's figures of F. 

 distinctuin are concerned, there is obviously no separation 

 between his species and my specimens, some of which show 

 the intermediate characters to F. pavo?tinum. The figures of 

 the two species, however, present marked differences in the 

 smoothness of the external epitheca, but Nos. i and 2 above 

 resemble F. pavoniimm in being quite smooth, while in the 

 rest lines of growth and, in some cases, distinct ribs can be 

 seen. (Figs. 18—21). 



F. patens and F. australe, both Moseley, have, so far as I 

 could see from an examination of the specimens, no specific 

 differences from the species under consideration. No, 2 above 

 shows a cutting away of the septal borders close to the margin 

 of the calicle, a character not found in the other specimens 

 from the same dredging. In the specimens enumerated it is 



* Measurements in millimetres, t These numbers, being taken from spirit 

 specimens, possibly slightly exceed those here recorded. ^ This specimen was 

 brought up together with a large number of oorallites of F. riibrum, its external 

 lesemblance to small specimens of which is at once apparent from the measurements. 



