DALL: MOLLUSCA AND BRACHIOPODA., 
[Sw) 
bo 
~J 
Turritellidae. 
Turritella mariana DALL1, n. sp. 
Plate 11, figure 14. 
Shell slender, pale pinkish-brown, acute, with about eighteen whorls; suture 
rather obscure, not appressed; whorls strongly constricted in the middle, a sharp 
keel on each side of the constriction, which in the last two or three whorls is undulate 
or obscurely beaded ; nucleus lost; on the earlier whorls the keels are entire and 
the whorl slopes about the same distance from each to the adjacent suture; on 
the latter whorls there is a single thread behind the posterior keel and two in the 
trough between the two keels, all somewhat undulate, low, and inconspicuous ; 
base of the whorl with a sharp carina upon which the suture is laid; within the 
carina deeply concave, with well-marked lines of growth and microscopic spiral 
striae; aperture rounded-quadrate, the outer lip with the margin at first retrac- 
tive to a wide smus nearly coincident with the posterior keel, then prominently 
protractive to the basal keel, thence in a deeply excavated curve to the pillar, 
which is thin and arcuate, short and gyrate, about a narrowly pervious axis. 
Lon. of shell, 25; of last whorl, 6; of aperture, 3; max. diam. 5 mm. 
U. 8. 8. “ Albatross,” station 8427, near the Tres Marias Islands, in 80 
fathoms, rocky bottom, temperature 51°.2 F. U.S. N. Mus. 123,036. 
Although there is only a single specimen of this species, it is in excellent pres- 
ervation, and on comparison with a large series of the Pacific Coast species could 
be identified with none among them. 
Solartide. 
ARCHITECTONICA Botren. 
Architectonica Bolten, Mus. Boltenianum, 1798, p. 78; first species, T’rochus perspec- 
tivus Gmelin. 
Solarium Lamarck, Prodrome, 1799, p. 74; sole ex., T’rochus perspectivus Linné. 
Architectoma Gray, P. Z. 8. Lond., 1847, p, 151; err. typ. pro Architectonica. 
Architectonica radialis DAtt, n. sp. 
Shell small, depressed, pale yellowish over a white inner layer, the apical 
whorls lost but about three whorls remaining; surface very badly eroded, only 
remaining in small patches, one of which on the last whorl shows four arcuate 
radial riblets on the top of the whorl in a space of 3.5 mm., with wider inter- 
spaces, crossed by faint indications of spiral striae ; near the aperture these riblets 
(which presumably were present over most of the spire) are obsolete; and the 
spiral lines extend from a (very slightly) channelled suture to an obtuse angle 
