MUSEUM OF COMPARATIVE ZOOLOGY. 367 



carina lighter than the rest of the upper surface; general outline from nucleus 

 to basal periphery somewhat concave; base concavely excavated within the 

 margin, slightly convex toward the centre; nucleus whitish, smooth; whorls 

 gently rounded, closely appressed to the almost invisible suture and excavated 

 in front of it ; the last whorl flatter above, more rapidly enlarging at the pe- 

 riphery. Sculpture of small regular waves on the carina, about six in a space 

 of 5.0 mm., giving a minutely scalloped outline; behind this a strong nod- 

 ulous thread, revolving like a string of small uniform beads ; then a more 

 slender thread more finely beaded ; in all eleven regularly alternating revolv- 

 ing threads at the beginning of the last whorl; this sculpture is very uniform 

 all over the upper surface; base polished, smooth, except for two or three 

 faint beaded lines and grooves about the pillar, and faint longitudinal and 

 transverse growth markings; aperture nearly twice as wide as high; lower lip 

 with a beautifully concavely arched outline, falling much behind the upper 

 one; margin simple, except for sculpture marks; pillar short, arcuated, pearly, 

 simple, ending in a slight point. Height of shell, 21.0; extreme width, 26.5; 

 height of aperture, 6.0 mm. 



Habitat. Stations 265 and 299, near Barbados, in 576 and 140 fms., coral 

 bottom, temperature 40° to 56°.5 F. 



A single specimen and a fragment of this extremely lovely shell were ob- 

 tained as above. It is well distinguished from its congeners, none of which 

 closely resemble it. The color is evenly distributed in the type, but, as in 

 C. Bairdii, it is likely that the color may be more dark and pronounced in 

 more northern localities. The marked features are the concavity of the slope 

 of the spire and of the outer portion of the base, the polished base contrasting 

 with the regularly beaded upper surface, and the delicately notched carina at 

 the periphery. It is one of the most attractive species of the genus. 



Calliostoma orion n. s. 



Plate XXVIII Fig 2. 



Shell small, white, acutely conical, with a glassy sinistral globular nucleus 

 and five (or more) whorls; radiating sculpture consisting of faint incremental 

 lines; spiral sculpture on the upper surface of the last whorl of seven nodulous 

 revolving lines, beginning at the suture; the first, third, and fifth have larger 

 nodules elongated in the direction of the lines, the second and fourth are more 

 finely and simply evenly beaded. A single fine raised not nodulous thread sep- 

 arates each pair of the preceding ; the sixth and seventh spirals are smaller than 

 the fifth and close together; they stretch over a series of more distant swellings, 

 and are concavely impressed between them; as these lines form the periphery, 

 this gives a wavy or scalloped outline to the base, which has about eighteen 

 such waves arranged to a certain extent in pairs, the distance and concavity 

 between them alternating greater and less. The longer waves are articulated 

 with pale brown, and the first and third spirals show traces of a similar ar- 

 ticulation. The base is pretty sharply carinated, flattened, and finely spirally 



