HETEROPORA. 201 



13. Ceriopora tenuissima, Etallon, 1861. 



SYNONYMY : 

 Heteropora tenuissima, Etallon, 1862, op. cit. ser. 3, t. vi. p. 214. 



Distribution. Diceratian : Yalfiu and Septmoncel, Haut-Jura. 



Family HETEROTRYPID^, TJlrich. 



Diagnosis. Trepostomata in which the zooecia are simple, pris- 

 matic, or cylindrical, with a well-marked divisional line between 

 the walls of adjacent zocecia. Mesopores present. Diaphragms 

 numerous and horizontal. Neither cystiphragms nor interzooecial 

 yesicles present. 



HETEROPORA, Blainville, 1834. 



SYNONYMY : 



Millepora, pars, Laraouroux, etc. 

 Ceriopora, pars, Goldfuss, etc. 

 Monticulipora, pars, D'Orbigny. 

 Spiropora, pars, Def ranee. 

 Cricopora, pars, Blainville. 

 Reptomulticrescis, D'Orbigny. 

 Multicrescis, D'Orbigny. 

 Crescis, D'Orbigny. 

 Polytrema, D'Orbigny. 

 Nodicrescis, D'Orbigny. 



Diagnosis. Heterotrypidse with prismatic or suh cylindrical 

 zooecia. Mesopores numerous. Acanthopores absent. Walls of 

 zooecia thin. Diaphragms horizontal ; numerous. Zoarium 

 branching or massive. 



Type species. Heteropora cryptopora (Goldfuss), 1827. 



Affinities. This genus was originally included by Goldfuss 

 under his genus Ceriopora. Blainville separated it for those 

 Ceriopora-like forms in which the zocecia are of two distinct 

 sizes. As a rule, most subsequent palaeontologists have accepted 

 the genus; the most important exception is Haime, who denied 

 that the dimorphism was even of specific value. 



Instead of this, I am constrained to place them in distinct 



