SPECIES FROM THE PSAMMITES DU CONDROZ (FRANCE). 

 Sabmitted by Professor Charles Uabrois, UniTeriity of Lille. 



DicTYospoNGiA MoBiNi, Barpois (sp.). 



Platk xltz, Fiob. 1,2. 



1883. Dictt/ophf/ton Mormi,'Ba,rrois. Annalea de la Soc. G60I. du Nord, 

 vol. xi, p. 83, pi. 1, figs. 2 a-c. 



This species is one of the smooth conical sponges for which the generic 

 term Dictyospongia has been here proposed. The specimen which we have 

 examined represents the upper portion of the cup including the a])erture, 

 which is regular and apparently unornamented. The impression of the reticu- 

 lum is obscurely retained and extremely fine. Professor Barbois has figured 

 not only the specimen here illustrated, but also one which retains the basal 

 part of the cup and shows that the expansion of the sponge was gradual and 

 uniform. 



Locality. Jeumont (Departement du Nord), Brittany. 

 Htdnoceras Barroisi, nom. nov. 



Platb xlti, Figs. 3, 1. 



1883. Dictyophyton tuberosum, Barrois. Annales de la Soc. G60I. du Nord, 

 vol. xi, p. 82, pi. 1, figs. 1 a-e. 



Attention has already been directed to the fact that the species described 

 as Dictyophyton tuberosum, Conrad, by Professor Barrois, in his memoir on 

 the DiCTYOspoNGiD^ of the Psammites du Condroz, proves, after a careful 

 revision and comparison of the nodose sponges, to represent a specific form 

 which is not, to our knowledge reproduced among the American species of 

 this genus. The distinctive characters of the French fossil lie in (1) the very 

 deep and broad horizontal constrictions which render the node-bearing ridges 

 very conspicuous; (2) the sharply defined prism-faces, their margins being 

 distinctly continuous ridges extending from the apex and crossing the hori- 

 zontal constrictions ; (3) a faint median ridge dividing each of the eight prism- 

 faces ; (4) the low, elongate and sharp nodes forming ridges by fusion with the 

 vertical prism-margins. The single specimen is broken across the third node- 

 bearing ridge and there is, hence, no means of inferring the number of such 



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