68 PATAGONIAN EXPEDITIONS : PALEONTOLOGY. 



CYCLOSTOMATA. 



Fam. LICHENOPORIDsE Sm. 



Gen. RETICULIPORA d'Orb. em. Wat. 



12. RETICULIPORA PATAGONICA Ortmann. 



Pi. XII, Fig. 2-. 



1900 Reticulipora patagonica Ortmann, in: Amer. Journ. Sci., v. 10, p. 



37. 



Zoarium reticulate, fenestrae of the reticulations 2-4 mm long, and 1-2 

 mm broad, irregular. Branches much compressed in section, about 2 

 mm deep. Broad lateral surfaces of the branches with slightly exserted, 

 tubular zocecia, which are rather crowded and form irregular transverse 

 rows. Besides the zocecial openings there are smaller, non-tubular ones 

 at the sides of the branches. On the front of the branches a median 

 lamina rises as a distinct narrow median ridge. On the back part, the 

 branches are rounded, and show very small openings. 



Remarks: In the possession of intermediate pores this species does not 

 correspond to the original diagnosis of the genus given by d'Orbigny 

 (1859, p. 903), but it agrees with Waters' conception of Reticulipora. For 

 the same reason the present species and the genus Reticulipora of Waters 

 cannot be united with Idmonea, as Zittel does (1880, p. 599). I leave 

 our species in the genus Reticulipora, since it comes extremely near to 

 Ret. transennata Waters. 



Record of specimens: Mouth of Santa Cruz River; fragments of about 

 10 colonies. 



Affinities: This species is very closely allied to Reticulipora transennata 

 Waters (1884, p. 689, pi. 30, f. 2, 3, 6, 7), from Aldinga, South Australia, 

 which locality is regarded as Eocene. Indeed, it resembles this one so 

 much that I entertain some doubt as to the specific difference of both. 

 The only differences I am able to point out are : the branches of the 

 zoarium seem to be stronger in our species (compare fig. 3 of Waters), 

 and the zocecial openings appear to be more crowded (see fig. 7, 1. c.). 



