MUSEUM OF COMPARATIVE ZOOLOGY. 43 



Ovulactaeon Meekii n. s. 



Plato XXXIII. FiicH. 3, 4. 



Shell with the outline of a small Cyprcea like C. edentula, widest in its pos- 

 terior third, white, polished with fine, distinct, impressed incremental lines, 

 and the faintest trace of spiral linear markings ; a depressed line or sulcus 

 indicates a previous resting stage half a Avhorl behind the present thickened 

 aperture in the older specimen ; in the younger, the varical sulcus is three 

 quarters of a whorl behind the aperture. The apex in the older shell is per- 

 forate, the whorl rounding over to the perforation, and the spire invisible ; in 

 the younger specimen the perforation is proportionally wider, and about half 

 a turn can be seen. The lines of growth become stronger and more regularly 

 grooved as they pass over the summit into the pit. The aperture is very 

 narrow, curved with the profile of the shell, and extending beyond the sum- 

 mit. Unlike Cyprcea, the thickening of the outer lip is altogether internal, 

 simple, and smooth; the callus opposite is narrow, with a sharply defined 

 abrupt outer margin, and the inner margin raised sharply up parallel with the 

 outer lip, with which it is continuous at the extremities ; the flat part of the 

 callus is widest anteriorly, polished but not smooth, but the raised edge is 

 without teeth or transverse striation of any sort. The extremities of the aper- 

 ture are elevated to follow the profile of the body of the shell. Lon. of largest 

 specimen, 5.5 ; max. lat. 3.0 mm. 



Habitat. Off Havana, Sigsbee, in 450 fms. "West of North Bernini, Baha- 

 mas, in 200 fms., sand, Dr. Rush (U. S. Nat, Mus., No. 61228). 



This extremely interesting shell is well shown by the figure. There can be 

 little question as to its probable relations. The characters of the aperture are 

 essentially different from anything among the Cyprceidce, and it has not the 

 polished lacquer which species of that family owe to the expanded mantle- 

 margin. Only one specimen was obtained at either locality. 



Family RINGICULID^. 



Genus RINGICULA Deshayes. 



Section RINGICULINA Monterosato. 



Ringicula nitida Verrill. 



Ringicula nitida Verrill, Am. Journ. Sci., 3d series, Vol. V. p. 16, Jan., 1873. 



(Extra copies sent out Dec. 13, 1872.) Dall, Bull. M. C. Z., IX. p. 97, 1881. 

 Ringicula leptocheila Brugnone, Misc. Malac., p. 18, fig. 11, 1873. Agassiz, Three 



Cruises of the Blake, II. p. 70, fig. 291, 1888. 

 '^Ringicula peracuia Watson, Journ. Linn. Soc, XVII. p. 292, 1883. Chall. Gastr., 



p. 636, pi. xlvii. fig. 11, 1886. 



Habitat. Fossil, Pliocene of Italy, Brugnone, and recent in the Mediterra- 

 nean. Bed of the Gulf Stream, Pourtales, in 447 fms. Yucatan Strait, 640 fms. 



