26 reef building taxa described. Corals (especially tabulates) dominant in framework facies. 15 genera of rugose corals (mostly solitary).
Up to 15 m thick massive reefs in shallowing upward sequence. Proximal carbonate ramp. 
Small and scarce macroborers evident on plates of ref. 1595.

Abstract of ref. 1595:
From four outcrops of the Portilla Fm. and one outcrop of the Candas Fm. in the W Cantabrian Mountains 17 species and subspecies of solitary and phaceloid rugose corals are described. They belong to 15 different genera. The stratigraphical classification of four of the localities in question as Upper  Givetian is confirmed by means of the identified coral faunas, and this age is also probable for the fifth locality. The rugose coral genera BREVISEPTOSIA n. gen. and SINAXIS n. gen. are erected in this paper; moreover the following 13 new species and subspecies are described and figured: Schindewolfia plena n. sp., Neaxon variabilis n. sp., Catactoechus bonarensis n. sp., Metrionaxon transitorius n. sp., Famennelasma antiquum n. sp., Breviseptosia pulchra n. gen. et n. sp., Sinaxis bulbosa n. gen. et. n. sp., Cyathophyllum (C.) postarduum n. sp., Thamnophyllum caespitosum leonense n. ssp., Acanthophyllum confusum n. sp., Stringophyllum buechelense cantabricum n. ssp., Stringophyllum crassimarginatum n. sp. and Solipetra fontainei n. sp. The number of genera and species of the normally ahermatypic classified small solitary corals without dissepimentarium is unusually great with respect to the  reef facies of the Portilla Formation. A part of them even occurs together with compact flat colonies of back reef corals of the 'reef  meadows' or even together with large solitary corals. So we have to assume that the 'Portilla environment' of the investigated localities was characterized by a very narrow-spaced irregular morphological pattern of its sea bottom. 