14 Dr. H. A. Nicholson on some new or 



means of separating from each other the young individuals of 

 the two species, and agree with one of the best distinctive 

 characters of the adults. The very small examples of both 

 species not only have the prseoperculum furnished with spines, 

 but they have also a scapular spine and a postsupraorbital 

 spine on each side. The larger specimens have a rather elon- 

 gate form, but are at the same time pretty thick, and not 

 compressed as at a later period ; the dorsal, which is compara- 

 tively rather low, originates, in the adult G. equisetis, at a 

 point not far distant from the posterior margin of the eye, 

 in younir individuals above the posterior margin of the pras- 

 operculum, in still younger individuals between the latter 

 and the gill-cleft, in the adult G. hippurus above the posterior 

 margin of the pupil, in the youngest individuals above the 

 gill-cleft, &c. The system of coloration which distinguishes 

 the different ages of these two species will be easily under- 

 stood by the aid of the figures. 



[To be continued.] 



II. — On some new or imperfectly-known Species of Corals 

 from the Devonian Rocks of France. By H. Alleyne 

 Nicholson, M.D., D.Sc, F.R.S.E. 



[Plate I.] 



Some little time ago M. Daniel OEhlert, the able Curator of 

 the Museum of Natural History in Laval, was good enough 

 to send me for examination and determination a number of 

 corals from the inferior Devonian deposits of the neighbour- 

 hood of Laval, the stratigraphical and palseontological 

 relations of these deposits having been made by him a subject 

 of special study. Among the specimens contained in the 

 collection submitted to me were some entirely new forms, as 

 well as some which have not yet been fully worked out ; and 

 I propose on the present occasion, in accordance with M. 

 CEhlert's wish, to give a brief description of the more im- 

 portant and striking of these. 



Endophyllum (Ehlertij Nich. 



Spec. char. Corallum composed of subcylindrical coral- 

 lites, which are either not in contact at all or, at most, touch 

 each other only at limited portions of their circumference. 

 The diameter of the corallites along their longest axis is from 

 20 to 25 millims. Each corallite is enveloped in a distinct 



