112 



have called the cup may be the base, the small projection in the middle 

 being the point of attachment. In that case, this species would be a 

 Ptychoi?]iyllum, The supposed base is worn away in the specimen, so that 

 this point cannot be determined at present. The extraordinary compact- 

 ness of the internal structure separates this from an}- described species 

 from the Silurian rocks of America. 



Locality and Formation. — Anse a la Vieille, Bay of Chaleurs. Middle 

 Silurian. 



Collector. — Sir W. E. Logan. 



Cyathophyllum Pasithea. (N. sp.) 



Description. — The specimen upon which this species is founded is cylin- 

 drical, 21 lines in length and 10 lines in diameter. In the longitudinal 

 section, the inner area is 3|^ lines in diameter, filled with large cells, the 

 tabulae being very thin and not extending across but irregularly coalescing, 

 thus forming acutely lenticular vesicles, from 1 to 3 lines in length, 

 arranged in curvmg lines, the convex side towards the base of the corallite. 

 In the outer area the vesicular tissue is very fine, but distinct, and 

 indicated in the polished section by two sets of Imes, one curving upwards 

 and the other downwards, crossing each other nearly at a right angle. 

 There are six or seven lines in the width of one line, and the cells are on 

 an average about one-sixth of a Ime across. In the transverse section 

 there are seen about 70 radiating septa, which extend about two-thirds of 

 the way to the centre. The surface is longitudinally marked with distinct 

 ridges, about three in one line, separated by fine deep sulci. It is also 

 transversely annulated by strongly projecting rings of growth, most promi- 

 nent and angular on their upper sides. Of these there are six in the 

 length of 21 lines. 



This species differs so widely from all the others described in this paper, 

 that a comparison is scarcely necessary. Owing to the peculiar construc- 

 tion of the cells in the outer area, that is to say, curving downwards as 

 well as upwards, I suspect that it will turn out to be a Heliophyllam. 



Locality and Formation. — Anse a la Vieille, Bay of Chaleurs. Middle 

 Silurian. 



Collector. — Sir W. E. Logan. 



Cystiphyllum maritima. (N. sp.) 



Description. — The only specimen of this species I have seen is turbinate, 

 gently curved, 2^ inches in length, and about the same in width at the 



