358 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Cibao region of Haiti and Porto Rico. Ceri<m striatella , C. microstoma , Pseudobalea 
dominicensis , Guppya gundlaclii , and Pupa pellucida have a similar distribution, and 
the present distribution of these species would seem to be a hint at a period within 
their existence when there was a continuous land connection between the three islands. 
The form of the catalogue needs no special explanation. It may be remarked 
that when there is no reference to an} 7 authority for the presence of a species in the 
Porto Rican fauna, it may be understood to have been collected by the United States 
Fish Commission. 
For convenience of reference, a check list of the species included in the report 
follows the main body of the text, together with a list of the Fish Commission 
stations at which mollusks were collected. 
We are under obligations to Mr. W. E. Hoyle, of the Owens College, Man- 
chester, England, for examination of a species of Octopus , a group upon which he is 
regarded as an authority; also to Dr. Rudolph Bergh, of Copenhagen, Denmark, for 
the determination of a nudibranch. 
U. S. National Museum, Division of Mollusks, 
January , 1901. 
Class CEPHALOPODA. 
Order DIBRANCHIATA. 
Suborder 00T0P0DA. 
Family OCTOPODIDAi. 
Genus OCTOPUS Lamarck, 1799. 
Animal with a rounded body; the eight long arms provided on their inner surfaces with two rows 
of suckers. The third right arm of the male is altered for sexual purposes. Type, 0. vulgaris Lamarck. 
Octopus americanus d’Orbigny. 
Octopus vulgaris Lamarck, var. americanus d’Orbigny, in Sagra, Moll. Cubana, i, p. 14, pi. i, 1841. 
One small specimen is in the Fish Commission collection, taken at Ensenada Honda, Culebra, but 
the arms are so badly mutilated that it can not be identified with certainty. 
Octopus granulatus Lamarck. 
Octopus granulatus Lam., Mem. Soc. Hist. Nat. Paris, i, p. 20, 1799. 
Body slightly flattened, with a median ventral groove; mantle opening extending nearly half way 
round the body; head a little narrower than the body; eyes prominent; arms rather short, stout; the 
first three suckers in a nearly straight row; surface covered with small warts, violet brown; under a 
lens it is seen to be finely covered with dots. Our specimens are so contracted by the alcohol that 
measurements can not be given. 
Porto Rico, no special locality, three fine specimens; San Juan Harbor, one specimen; Ensenada 
Honda, Culebra, several young specimens. 
Octopus tehuelchus d’Orbigny. 
Octopus tehuelchus d’Orbigny, Voy. Am. M£rid., p. 27, pi. I, figs. 6, 7, 1835. 
Body slightly flattened and having a well-marked ventral groove, smooth; arms elongated, the 
upper pair shorter; umbrella extending one-fourth the length of the arms; siphon rather small. Color 
brownish, finely dotted. Entire length of largest specimen, 90 mm. 
Ensenada Honda, Culebra, six specimens; Ponce, Porto Rico, one specimen. 
