mollusc a of porto rico. 
359 
The following form does not seem to agree with anything that has been described, and is 
perhaps new. 
Octopus tuberculatus Blainville, junior? 
? Octopus tuberculatus Blainville, Diet. Sei. Nat., xliii, p. 187, 1826. 
Body slightly flattened, with a well-marked median ventral groove; mantle opening extending 
about two-fifths of the way around the body; siphon rather long, nearly smooth, not attached along 
the base of the arms; head a little narrower than the body; eyes prominent; arms long, nearly equal 
in length; umbrella small, more developed at the sides than above; suckers small, prominent, radially 
ridged, first four in a slightly zigzag line; hectocotylized arm ending in a long, roughened spur; surface 
marked with somewhat scattered, small pustules and wrinkles, and having a few curious warty 
processes on the back of body and head; some of these are finger-like and two, situated close to the 
eyes and partly between them, are branched. 
Color pale violet above, the whole surface sprinkled with minute dots; there are two eye-like 
circular dark spots, one on each lower side of the head, which appear to be permanent. 
Length of body, 35 mm. ; of arms, 60 mm. 
St. Thomas, one specimen. 
This small Octopus presented a very special appearance, owing to the two sharply defined dark 
spots on the head; and, suspecting that it might be new, it was submitted to Mr. W. E. Hoyle, of 
Manchester, England, an authority on these animals, for examination. He kindly reports that the 
specimen is young and may perhaps be the immature form of 0. tuberculatus Blainville, but that it 
appears inadvisable to describe it as new in the absence of full-grown specimens. 
0. tuberculatus has been recorded from the Antilles and, if found at St. Thomas, may probably 
also inhabit Porto Rico. 
Suborder SEPIOPHORA. 
Family LOLIGINID/E. 
Genus L0LIG0 Lamarck, 1799. 
Loligo gahi d’Orbigny. 
Loligo gahi d’Orbigny, Voy. Am6r. M6rid., p. 60, pi. in, figs. 1, 2, 1835. 
Four specimens of what are probably the above were taken in Mavaguez Harbor, Porto Rico, but 
they are not in condition to be described. 
Family SPIRUUD^E. 
Genus SPIRULA Lamarck, 1801. 
Spirula australis (Lamarck) Pelseneer. Plate 56, fig. 4. 
Spirula australis Lam., An. sans. Vert, vil.p. 600, 1822: Encyc. M6th. pi. 465, fig. 5, a, b. 
Several imperfect shells of the above were collected at Hucares, Porto Rico, and Ensenada Honda, 
Culebra. The species has an almost universal distribution in warm seas, and millions of shells are 
thrown up on the seashore. Few animals have ever been obtained, and these are for the most part in 
an imperfect condition. 
There are several species of Spirula which can not be discriminated by the shells alone. In the 
paper by Huxley and Pelseneer on the Spirula of the Challenger voyage the name australis given by 
Lamarck is fixed on the Antillean species. Some additional data relating to this form are printed in 
Science, n. s., vol. in. No. 59, Feb. 14, 1896, pp. 243-245, from a specimen taken from the mouth of a fish 
trawled by the Albatross in the Gulf of Mexico, in 324 fathoms. 
