540 A, E. Verriil— Catalogue of Marine Mollusca. 
TECTIBRANCHIATA. 
Actzon nitidus Verrill, sp. nov. 
PLATE LVIII, FIGURE 21. 
Auriculina insculpta Verrill, Proc. Nat. Mus., ili, p. 381. 1880, (non Mont. sp.) 
Shell small, white, translucent, glossy, elongated, apex obtuse. 
Nuclear whorl rather large, regular. Whorls six, flattened at the 
periphery, gradualiy increasing, slightly roundly shouldered, sculp- 
ture delicate, wavy, incised spiral lines, more distant and distinet on 
the anterior part of the body-whorl, becoming finer, closer, and more 
wavy behind the middle, obsolete near the suture, except one fine, 
subsutural groove; suture impressed, or slightly canaliculate. Aper- 
ture narrow-ovate, much contracted posteriorly, a little produced an- 
teriorly ; columella spirally twisted, the inner edge forming a slightly 
raised fold. 
Length, 8"™; breadth 8™™; length of body-whorl, 5°5™"; length of 
aperture, 3°5™™; its breadth, 1:8™™. 
Stations 892 and 947, in 487 and 312 fathoms, 1880 and 1881, south 
of Martha’s Vineyard. 
The shell formerly recorded as Auriculina insculpta was a young 
dead specimen of this species. 
Ringicula nitida Verrill. 
Ringicula nitida Verrill, Amer. Journ. Sci., TH, vol. v, p. 16, 18 
Smith and Harger, Trans. Conan. Acad., iii, p. 48, pl. 1, fig. 2, 18 
Dall, Bulletin Mus. Comp. Zool., ix, p. 97, 1881. 
-—3; Verrill, in 
Gulf of Maine, 110 fathoms, “ Bache,” 1872. 
Dredged at ten stations, off Martha’s Vineyard, in 1880 and 1881, 
in 100 to 500 fathoms; stations 947, 949, 994, 997, in 100 to 368 
fathoms, 1881. 
Off Florida, 447 fathoms; Gulf of Mexico and Yucatan Straits, 
339 to 640 fathoms (t. Dall). 
Mr. Dall records specimens 7°5™™ long, 5™" broad, which is larger 
than any of ours, which seldom exceed 5"™ in length. 
CHoRIsTID#, fam. nov. 
The peculiar structure of the following shell, its animal, and the 
radula will not allow it to be placed in any established family. 
Therefore I propose to make it the type of a new family, Choristide. 
This family may be characterized by the heliciform shell, with the 
perisotraca continuous between the whorls; lip continuous ; columella 
