Southern reef tract. See reef 3136 for further remarks.
Sponges: Inozoans (Peronidella, Grossotubenella), spinctozoans (Amlysiphonella, Colospongia, Sollasia ...), calcareous algae, Tubiphytes, crinoids, Archaeolithoporella, 'hydrozoans' and bryozoans (Fistulipora, Fenestella) as reef builders