122 



The specimens are smaller, but otherwise closely correspond 

 in every particular with the types in the British Museum. All 

 have the inner edges of the septa against the columella sinuous 

 as described, but there is rather more marked difference in size 

 between the primary and secondary septa, which are sub- 

 equal, and the tertiary. One specimen shows growth lines 

 clearly. Nos. II. and IV. have an appearance as if formerly 

 broken ; it is, however, due to the epitheca overgrowmg the 

 edge of the calicle and the subsequent regrowth of the polyps. 



III. THE ANATOMY OF THE TURBINOLIDAE. 

 I. GENERAL OBSERVATIONS. 



I have below appended some remarks on the anatomy of 

 such of the Turbinolidae as I have been able to examine. The 

 results, so far as the classiftcatory characters of the different 

 genera are concerned, may be seen by a glance at the accom- 

 panying table, in which I have included Flabellum rubrum and 

 pavoninum, of which I previously gave an account, Para- 

 cyathus farvulus, a reef species with commensal algae from 

 my own Maldive collection, and Caryophyllia smithi from 

 Norway. 



The investigation assists but little in any attempt to find out 

 the relationship of the different genera to one another. I have, 

 however, employed the examination of the polyps wherever 

 possible to checK the species, which, in the first place, I deter- 

 mined by their coralla alone. Having already seen that the 

 polyp anatomy did not differ in Flabellum rubrum, in spite of 

 iis considerable variation in growth form, I examined polyps of 

 the most widely-divergent growths, of Heterocyathus aequi- 

 co status (lo), Paracyathus farvulus (4), Trochocyathus raw- 

 sonii (4), and Caryophyllia epithecata (2). Differences due 

 t(j age, the forms of the coralla, states of contraction of the 

 polyps, conditions of feeding, etc., were common, but I found in 

 no case any in the gross anatomies of the different specimens 

 of the same species. A regular difference lay in the number of 

 the mesenteries, which sometimes increase with age, entailing a 

 corresponding increase in the number of the septa. The mesen- 

 teries reaching the stomodoeum and possibly the tentacles 

 acquire their adult number at a very early age, and remain 

 constant. Throughout the collection either half or all the 

 septa were entocoelic, and, although it may have been due only 

 to age, it was a rule that generative organs were present in 

 the pairs of mesenteries on either sides of all the septa in each 

 system, save those of the highest cycle, and in them alone. 



