754 PROF. A. DENDY AND MR. K. W. H. ROW ON 



Genus 19. Heteropia Carter [1885-1886] (emend.). 



Diagnosis. Canal system sy conoid. Dermal cortex with colossal 

 longitudinal oxea. 



For illustrations of this genus see Row [1913 MS.]. 



This genus stands in precisely the same relation to Grantessa 

 that Ute does to Grantia. It is noteworthy that, in all known 

 species of this genus, as in the more highly developed species of 

 Grantessa, the tubar skeleton has been reduced to the subgastral 

 sagittal triradiates, supplemented by the subdermal pseud osagittal 

 triradiates, and has thus become " inarticulate." 



The genus Heteropia was diagnosed by Carter in July 1886 as 

 follows : — " Calcareous sponges in which the wall is simply 

 composed of sarcode supported on large sagittiform triradiates, 

 whose heads are fixed in opposite sides of it respectively, and 

 whose long shafts, extending perpendicularly across it, more or 

 less overlap each other." 



Most of the species placed by Carter in this genus belong 

 to the earlier genus Grantessa of von Lendenfeld. There is^ 

 however, one of his species, Heteropia ramosa, which is dis- 

 tingtiished by the presence of colossal longitudinal dermal oxea, 

 and which may be regarded as the type of Carter's genus. It is 

 curious that Mr. Carter himself [1886] described it under the 

 name of Ajj/iroceras ramosa, whilst saying at the same time that 

 it belonged to his genus Heterojna. 



We recognise the following species as belonging to this 

 genus : — 



Section A. Without microxea. 



1. H. GLOMEROSA Boiverhank. 



Lettconia glomerosa ^owevhsaAz. [1872-1876]. 



2. H. RAMOSA Garter. Type species of the genus. 



Aphroceras ramosa Carter [1886]. 



3. H. SIMPLEX Roui. 



Heteropia simplex Row [1913 MS.]. 



Section B. With microxea. 



4. H. RODGERi Lamhe. 



Heteropia rodgeri Lambe [1900]. 



Genus 20. Amphiute Hanitsch [1894]. 



'anal system sy conoid. Both gastral 

 with colossal longitudinal oxea. 



For illustrations of this genus see Hanitsch [1895]. 



Diagnosis. Canal system sy conoid. Both gastral and dermal 

 cortices with colossal loneitudinal oxea. 



