322 SOLARIELLA. 



at margin ; aperture rhomboidal ; columella margin subdentate at 

 base. Alt. 5, diam. 7 mill. (Fischer.} 



Portugal, 3307 meters. 



Trochus (Solariella) lusitanicus FISCHER, Journ. de Conchyl. 1882, 

 p. 51. 



S. LISSOCONA Ball. PI. 48, figs. 23, 24. 



This species belongs to the same group as the last three mentioned 

 species, but is nearest to the last. The shell is more simply conical, 

 consisting of six and a half whorls, which glisten with that peculiar 

 spun-glass or flossy luster noticeable in so many abyssal species; the 

 nuclear whorls as in the last ; then the sculpture consists of two 

 lines closely appressed to the sutures, less prominent and less con- 

 spicuously provided with the angular projections than in the last 

 species. Between the upper and lower lines the surface of the whorl 

 is smooth, except for lines of growth, shining as above described, and 

 seems even a little concave. The nodules on the upper carina of one 

 whorl fit into the spaces between the nodules on the lower carina of 

 the preceding whorl, and thus alternate along the line of the suture 

 and give it a wavy character. The carina on the last whorl is seen 

 to be formed by two threads, which constitute the periphery, with 

 fainter angularities than the others. The base is somewhat inflated, 

 with two sharp, smooth threads between the periphery and the 

 nodulate boundary of the small funnel-shaped umbilicus. The lines 

 of growth are much as in the last species, the umbilicus is not in- 

 fringed upon by any reflection of the pillar-lip, and the aperture is 

 about as wide as high, and less distinctly rectangular. 



Alt. 5'5, diam. of base, 4'5. Lat. of aperture, 2 mill. (Dall.~) 



Northern Central Gulf of Mexico, 331 fms. 



Margarita lissocona DALL, Bull. M. C. Z. ix, p. 41, 1881 ; Solari- 

 ella lissocona DALL, Bull. M. C. Z. xviii, p. 381. t. 21, f. 8 1889. 



S. LACUNELLA Dall. PI. 51, figs. 32, 33. 



Shell in general form and sculpture much resembling the last, 

 but, without the nacreous coloring, stouter and coarser in every 

 respect, whorls five, the revolving threads on the upper side of the 

 whorls only seven in number (on the last whorl), of which the inner 

 two are crenulated by the radiating plications which otherwise are 

 visible only as radiating threads in the interspaces, the base rounded 

 with nine flattened revolving ribs separated only by incised lines 

 and crossed by delicate lines of growth. The umbilicus much 



