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



a. old branch exterior 

 and terminal cups and young one 

 growing from the side. 



Transverse section showing the 

 three areas and a bud (x) grow- 

 ing in the outer one. 



Vertical section. 



areas ; 1st, a cylindrical, de- 

 fined, complex axis composed 

 of irregularly blended vesicular 

 plates ; 2nd, a cylindrical, de- 

 fined area of strong, vertical, 

 radiating lamellae, connected 

 by thin transverse dissepi- 

 ments, only visible in the ver- 

 tical section ; 3rd, a wide, 

 largely cellular outer zone be- 

 tween the vertical lamellse and 

 the external wall of the stem, 

 composed of much- curved 

 vesicular plates extending ob- 

 liquely upwards and outwards : 

 outer walls of the tubes longi- Lonsdaleia 

 tudinally striated and trans- 

 versely rugose : reproduction i 

 by circular germs developed in 

 the cellular outer zone, and 

 springing at once obliquely 

 without the area of the parent stem, which continues its 

 growth uninterruptedly with the slender young stem project- 

 ing from one of the transverse rugosities of the external sur- 

 face ; the yoimg stem seems at first only composed of the axis, 

 and gradually acquires the inner lamelliferous and outer ve- 

 sicular zones as it increases in size. 



The little-known Erismatholites Madreporites duplicatus of 

 Martin's 'Petrificata Derbiensia' may be looked upon as the 

 type of this genus, which I have dedicated to Mr. Lonsdale as a 

 slight token of my admiration for his labours in illustrating the 

 structure of fossil corals. It will be seen from the above notice 

 to unite in itself the internal structure of Strombodes {Lithostro- 

 tion, Lonsd.) with the external character and mode of growth of 

 Cyathophyllum (C dianthus, &c.). 



Lonsdaleia crassiconus (M'Coy). 

 Sp. Char. Corallum forming groups or loosely connected masses 

 of elongate-conical stems, averaging 6 to 7 lines in diameter ; 

 surface with concentric wrinkles and coarse flexuous longitu- 

 dinal strise ; lateral branches rajndly expanding, conical, widen- 

 ing from their base at the rate of 6 lines in 9 lines of length : 

 horizontal section shows a central circular axis \~ line in dia- 

 meter of closely twisted laminae ; outside which is a circular 

 area 3 lines in diameter, of about twenty-four vertical radiating 

 lamellce, with few or no connecting vesicular plates between 



