28 GILBERT C. BOURNE. 



spicuous dark lines running down the centre of each septum. 

 The primary and secondary septa are but slightly thickened 

 towards the peripheral ends, the theca being mainly composed 

 of the heads of the tertiary septa. Fig. 7 shows that in the 

 upper part of the calyx the tertiary septa project from a stouter 

 thecal piece, the two together forming a T, of which the thecal 

 portion is the cross-piece. There are no sutures separating 

 the septal from the thecal portion. Lower down in the calyx 

 the tertiary septa die out altogether, but the cross-pieces, 

 representing their thecal portions, remain, and then the 

 section has precisely the appearance figured by Fowler in 

 Lophohelia. From the relations which obtain in Euphyllia I 

 am not disposed to think that the intercalated pieces figured 

 by him are essentially thecal structures sharply distinguishable 

 from septa. 



The structure of the dissepiments is quite similar to that of 

 Mussa. 



The specimens with which I worked were killed with the 

 tentacles fully expanded, but they were unfortunately too 

 much damaged to admit of a careful study. The tentacles are 

 numerous, short, and apparently correspond in number to 

 the septa, i. e. they are all eutocoelic, as is the case with the 

 latter. 



A well- developed " Randplatte " is present as in Mussa, 

 extending down the outside of the corallum for a distance of 

 1*5 centimetres. The structure and relations of the " Rand- 

 platte " are the same as those in Mussa, and do not require a 

 detailed description, the only difference of .importance is that 

 whereas the longitudinal muscles are generally absent on the 

 extrathecal portions of the mesenteries, they are present, 

 although in a rudimentary form, in Euphyllia. 



The appearance of the polyp on decalcification is quite similar 

 to that of Mussa, and affords ocular demonstration of the fact 

 that the corallum is wholly external to the polyp. The 

 internal anatomy of the polyp is of the highest interest. I 

 have not had the time to make so thorough an examination of 

 ts peculiarities as I should have wished, but hope to give a 



