MUSEUM OF COMPARATIVE ZOOLOGY. 265 



of dark reddish brown, and light colored primary spiral threads articulated with 

 elongated distant hrown spots. Whorls about iilteen, those after tlie nucleus 

 with a distinct median keel and obscure suture, the later ones with less promi- 

 nent median or })erhaps several indistinct keels; the last two whorls less closely 

 coiled in the adult, showing the posterior edge overhung by the preceding 

 whorl at the suture. Sculpture of pi'imary and secondary spirals very close 

 set, the primaries flatter and polished above; the finer or secondary spirals very 

 fine; both have a tendency to articulation, and the e])iderinis in the interspaces 

 bridges over fine sharp incremental lines. Irregularities of growth sometimes 

 sinudate faint longitudinal waves. Base similarly sculptured, slightly exca- 

 vated, bordered by a rounded not carinated edge; columella thin, arched; 

 outer lip thin, sinuous, subangulate anteriorly; aperture sub([uadrate, varying 

 with the sculpture and individual. Max. Ion. of shell, 31.0; max. lat., 8.0 mm. 



Habitat. West of Florida, 14-50 fms. ; off Cape San Antonio, 413 fms. ; 

 off" Sombrero, in 54 fms. Coast of North Carolina, near Hatteras, to the Gulf 

 of Mexico, Texas, and Yucatan, and the Antilles, in 3-73 fms., not living 

 deeper than 25 fms., U. S. Fish Commission. Fossil in Florida Pliocene. 



This interesting species is variable in color, and also in the form of the 

 whorls. Sometimes the latter are perfectly flat, at other times rounded. The 

 brown flammulae are occasionally absent. The striation appears very fine to 

 the naked eye. It is only under a magnifier that the separation into primary 

 and secondary spirals becomes evident. This fine striation will enable the 

 species to be recognized, whatever its color or form, which last, though variable, 

 is not remarkably so. This shell is sometimes bleached pure white, but I 

 have seen no white specimens which were fresh. It is, not rarely, of a delicate 

 rose or violet tint. That what appears to be so common a shell should have 

 gone unnamed until now would be singular, but it has probably been taken 

 by those who have collected it for the tip of a Vermicularia, or the young of 

 T. imbricata L. Complete and adult specimens are rare, fragments common. 

 I find nothing like it in the monographs. 



Section HAUSTATOR Montfort. 

 Turritella (Haustator) yucatecana Dall. 



Plate XXVI. Fig. 3. 

 Turritella yucatecanum Dall, Bull. M. C. Z., IX. p. 93, 1881. 



Habitat. Yucatan Strait, 640 fms. 



No other specimens of this interesting species have been received. Its 

 nearest relative would be T. pagoda Reeve, from New Zealand. 



The only other species of this group, which is known from this region is 

 T. {Haustator) variegata Linne, of which the T. imbricata is generally regarded 

 as merely a variety. It has been collected in Texas and the Antilles. 



Mesalia caribea Orbigny is reported from the Antilles, and has been united 

 with M. varia Kiener, of West Africa. I have never seen a specimen. 



