152 PROF. p. M. DUNCAN OK THE 



mentation has not the same direction as the synapticular 

 structures. 



A thick base shows openings somewhat rarely ; and in some 

 places costse unequal in breadth, spinulose and granular, are well 

 seen. 



The distinctions between this form and that already noticed 

 amongst the FungicB are the more slender synapticula, their ver- 

 tical position within and their discontinuous development near 

 the circumference, and the slit-like openings in the course of 

 large septa. It is evident that the morphology of these species of 

 Fungia is very similar. 



Part III. The Arrangement of the Hard Part of the Genus Herpolitha 

 (Herpetolitha auct.). 



Genus Herpolitha*, Esclischoltz. 



The corallum is compound, free, long and narrow; the upper 

 surface has indistinct calices of two kinds — one set occupy along 

 central line and are multilamellar ; and the other are placed irre- 

 gularly, have but few lamella, and are small. The septo-costal 

 rays are stout and long and alternately thick and thiu ; none 

 reach from the axial furrow to the circumference. The base is 

 perforated and echinulated. 



The genus may be said to embrace elongate slightly com- 

 pound Fungias ; and the typical species is HerpolitTia limosa, 

 Esper, described by Edwards and Haime {op. cit. vol. iii. p. 24), 

 = II.foliosa, Ehrb. 



The internal structures of the corallum have been hitherto un- 

 described, with the exception of a notice of the septa, which 

 Milne-Edwards and Jules Haime thus describe, " leur faces mou- 

 trent les cannelures verticales granulees " (their faces present 

 vertical granulated flutings). 



This is an unfortunate expression ; for, taken in relation to 

 the description of synapticula given by those authors in the first 

 part of the diagnosis of the Eungidse, the flutings, having of 

 course a ridge on either side, may naturally be considered to be 

 rows of synapticula. Indeed everybody who has the common 

 idea of the synapticulum being an exaggerated ornamental granule 

 will be misled, especially as the authors do not mention any 

 synapticula in the generic diagnosis. 



* Herpetolitha of more modern authors and restored by Klunzinger. See 

 his excellent criticism, op. cit. p. 68. 



