In a successful haul of the towing net, off the Island of Sardinia, I obtained a very beautiful Firola, which gave me a good opportunity of testing the truth of my former conclusions with regard to the economy of the Heteropoda in general, and of Firola in particular; and I have great pleasure in submitting the facts arrived at, with the accompanying enlarged figure of the visceral nucleus and the neighbouring parts, to the Royal Society of Edinburgh, as an appendix to my paper “On the Anatomy and Classification of the Heteropoda,” already brought under its consideration.