HYDROCORALLINE GENUS EllRINA. H79 



Taking these characters as guides it seemed to me that the 

 diagnostic characters of the three genera might be stated as 

 follows : — 



(a) Ooenosteum hard and compact, perforated by well- 

 defined coenosteal pores. Grooved spines turned 

 towards the apex of the branch. 



1. With short grooved spines and only one kind of 



dactylopore Errina, 



2. With long grooved spines and two kinds of 



dactylopores SpiniiJora, 



(h) Ooenosteum granular and reticulate, without well- 

 defined ccenosteal pores. Grooved spines turned 

 away from the apex of the branches or irregularly 

 placed Labio2wrci. 



If the three genera be joined together to form a subfamily, the 

 Errinina, this subfamily might be defined as follows : — 



Hydrophytum arborescent and irregularly flabelliform, gastero- 

 pores and dactylopores not aiTanged in cyclosystems. Gastero- 

 pores with a large brush-like style. Dactylopores without a 

 style. Some of the dactylopores protected by a grooved spine 

 (narial process) on the surface of the coenosteum. 



This arrangement of the genera, however, breaks down on 

 further analysis, and I see no other course than to arrange all the 

 species in three groups under the one generic name Errina. 



The genus Errina was founded by Gray in 1835 for a species 

 of coral found in the Mediterranean Sea and formerly called 

 Millepora aspera by Linnseus. 



As von Marenzeller has pointed out, Gray's description of the 

 spines in this species as '' Superne longitudinaliter fiss8e " is not 

 consistent with the description of the species known to Linnseus 

 and Esper. 



I have examined the type specimens in the British Museum, 

 and have found that Gray's description is not correct. The 

 spines in these specimens are irregular in arrangement, but where 

 they are isolated and not in clusters the groove is directed away 

 from the apex. Moreover, the character of the surface of the 

 coenosteum, the presence of a few small dactylopores without 

 grooved spines, and other features prove that this species is more 

 closely related to the type species of Labiop)ora than it is to any 

 of the other species of Errina. 



According to the system I had, at first, proposed the type 

 species of Errina would thus be a species of Labiopora and 

 Moseley's Errina ramosa would become the type species of the 

 genus. 



Such a proposal, therefore, would not only be contrary to the 

 rule of zoological nomenclature, but it would also be extremely 

 inconvenient. Moreover, one species at least {E. macrogastra) 

 would occupy an intermediate position, having a. surface similar 



