554 
A. E. Verrill — Catalogue of Marine Mollusca. 
This was taken in large numbers at numerous stations, in 1880 and 
1881, in the trawl. Living specimens were caught about 30 miles east- 
southeast of Block Island, at surface, October 2, 1880, by Messrs. 
Scudder and Edwards. 
I 
Cavolina tridentata (Forskai) H. and a. Ad. 
Hyalcea tridentata Lamarck, Anim. Ians. Yert., ed. II, vol. vii, p. 415. 
Cavolina tridentata H. and A. Adams. Genera, i, p. 51, pi. 6, figs. 1, la. 
Verrill, Rep. Invert. Auim. Vineyard Sd., in Rep. U. S. Fish Com., i, pp. 444, 
669 (auth. cop., p. 375), pi. 25, fig. 177, 1874. 
Figures 6, 7. 
Of this species I have received numerous specimens, with the ani- 
mal in good condition, obtained by Mr. Samuel Powell, from the 
stomach of a blue fish, at Newport, 
R. I., several years ago. In 1880, 
two living specimens were taken a 
few miles off Block Island, by Messrs. 
V. N. Edwards and N. P. Scudder, 
of our party. The fresh shells of 
this species were dredged by us in 
1871, near Martha’s Vineyard. In 
1880 and 1881, we found it in abundance and perfectly fresh, in all 
our outer dredgings, 70 to 100 miles off shore. It was particularly 
abundant at stations, 880, 892, 894, 947, 998. 
It was associated with Diacria trispinosa Gray and several other 
species, named below, but was far more numerous than any of the 
others. I have often taken it from the stomachs of actiniae, and from 
Archaster , and other starfishes, from the deep water stations. 
Cavolina uncinata (D’Orb.) Gray, 1850; H. & A. Ad. 
Hyalcea uncinata D’Orb, 1836. 
Rang, Hist. Nat. Pterop., p. 37, pi. 2. figs. 11-14, 1852. 
Cavolina uncinata Verrill, Amer. Journ. Sci., xx, p. 392, Nov., 1880; Proc. U. S. 
Nat. Mus., iii, p. 392, 1880. 
This occurred with the last off Martha’s Vineyard, 70 to 90 miles, 
stations 865, 867, 870, 876, 892, 894, 947. 
