130 Mr. F. M'Coy on some new genera and species of 



moved by Ehrenberg (Ueber Coralleuthiere des rothen Meeres, 

 &c.) and Lonsdale (Silurian System) to the recent genus Porites, 

 in which they were followed — probably without examination — by 

 many writers; Profs. Bronn (Leth?ea^ &c.), Phillips (Palaeozoic 

 Fossils) and others have however much more happily pointed out 

 their resemblance to Heliopora. The distinct walled tubular cells 

 visible in both sections, connected by cellular tissue, with their 

 twelve rudimentary lamellse, distinguish the present ancient corals 

 from the modern genera just named, for Porites has a minutely 

 reticulated corallum impressed by shallow polygonal undefined 

 cells on the upper surface, and presenting in the horizontal and 

 vertical sections an uninterrupted uniformly vesicular structure. 

 Heliopora agrees perfectly in external appearance, and in the 

 two sections exhibits the same characters of vesicular structure 

 connecting tubular cells with transverse diaphragms, but in it 

 the tubes have eighteen or more rudimentary lamellse, while 

 they ai'e constantly twelve in the present genus, which I only 

 know as yet in the older and middle palseozoic rocks. 



Fistulipora (M'Coy), n. g. 



Gen. Char. Corallum incrusting, composed of long, simple, cylin- 

 drical, thick-walled tubes, the , 

 mouths of which open as simple <0^"-^:5t>w>v 

 equal circular cells on the sur- j^'^^'i^T^O^fcccx 

 face, and having transverse 

 funnel-shaped diaphragms at 

 variable distances ; interval be- 

 tween the tubes occupied by a Fistulipora -. a. mode of growth, nat. 

 cellular network of small vesi- size, enveloping a ciinoid stem. 

 cular plates. ^- magnified surface and section. 



This genus is proposed to include the Manon cribrosum (Gold.) 

 of the Eifel, &c., and the two following species from the moun- 

 tain limestone. They have no affinity with the fossil sponges of 

 the genus Manon, with which the only previously known species 

 was classed by Goldfuss and others, but are more allied to the 

 so-called Porites of the palseozoic rocks [Palceopora, M'Coy), 

 from which they differ in the absence of the rudimentary radia- 

 ting or vertical lamellae to the cell-tubes. The sides of the tubes 

 do not seem to be ever perforated by connecting pores. 



Fistulipora minor (M'^Coy). 



Sp. Char. Cell-tubes with slightly prominent margins at the 

 surface, about four in the space of one line, rather less than 

 their own diameter apart, the intervening space composed of 

 from one to three rows of the minute vesicular cells. 



The tubes of this species are of so small a diameter that I have 



