dall: molltjsca and braciiiopoda. 327 



Turritellidae. 

 Turritella maxiana Dall, 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 suiure ; 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, tlie outer lip with the margin at first retrac- 

 tive to a wide sinus 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 she'll, 25 ; of last whorl, 6 ; of aperture, 3 ; max. diam. 5 mm. 



U. S. S. " Albatross," station 3427, 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. 



Solariidce. 



ARCIIITECTONICA Bolten. 



Architectonica Bolten, Mus. Boltenianum, 1798, p. 78; first species, Trochus perspec- 



tivus Gmelin. 

 Solarium Lamarck, Prodrome, 1709, p. 74; sole ex., Trochus per spectivus Linne. 

 Architectoma Gray, P. Z. S. Lend., 1847, p. 151 ; err. typ. pro Architectonica. 



Architectonica radialis Dall, n. sp. 



Shell small, depressed, pale yellowish over a wliite inner layer, tiie apical 

 whorls lost but about tliree whorls rcmaiuing; surface very badly eroded, only 

 remaining in small patches, one of whicii 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 



