194 Report of the State Geologist. 



the littoral fauna. There is scarcely any form, indeed, which 

 can not be referred to families already known. Representatives 

 of forms considered, extinct have been found there, but thus far 

 efforts have not brought to light any remains of the palaeozoic 

 faunas which it was hoped would be discovered. 



The fauna of the coast, in its most extended sense, descends to 

 about 400 meters. It embraces i\iQ calcareous sponges, Gorgonia^ 

 Comutula, Cidaris, Diadema, Bryozoans, Oysters, Cytherea, 

 Gasteropoda of every group. It is this which is the most gener- 

 ally represented in preceding geologic epochs. 



Lower down, from 400 to 1500 metres, are found the siliceous 

 Hexactinellida, the Sea Stars with great marginal discs [Pentago- 

 naster), the soft Echini; special forms of Crustacea, such as 

 Gnathojpliausia and the Polychelidce. Among fishes, Envy- 

 pharynx and Eathypterois. The Hydrocorallines and the Alcy- 

 onaria disappear toward 1000 metres. 



From 1500 metres to 3000 metres occurs the transition from 

 this fauna to the real abyssal fauna. The simple Polypi and the 

 Peniacrini dominate, whilst the silicious sponges become more 

 and more rare ; toward 2500 metres the simple Polypi in turn 

 disappear, and beyond 3000 metres the fauna is represented 

 exclusively by the symmetric Holothurians, with ventral flatten- 

 ing, the large Pycnogonidce and the blind decapod Crustaceans.^ 



The most important zone as regards the object of our present 

 consideration is that which extends from 400 to 20<>0 metres. 

 This is the Yerticordia zone of M. Fischer. It contains, with 

 types clearly affiliated to the actual littoral types, forms 

 which seem peculiar to the secondary period ; these are, for ex- 

 ample, the peduncled Crinoids, belonging to genera well repre- 

 sented at this epoch, as Pentdcrinus or other genera which are 

 very closely allied to extinct forms. The soft Echini, as Calveria, 

 recall with exactitude the Echinotburidse of the Chalk ; the Sal- 

 enidcB, characterized by the presence of a centro-dorsal plate 

 quite exceptional amorig the Echini; the Hulasteridm, repre- 

 sented by Pourtalesia, which recalls the genus Etfulaster, and 

 especially the Crustacea such as Willemoesia which represents 

 the Eryon of the Jurassic, are manifestly the last remains of a 

 part of the secondary fauna which, on our coasts, has completely 

 disappeared or has been radically transformed. Most naturalists 



