1913.] NATURAL SCIENCES OF PHILADELPHIA. 385 



•Granulation is weakly developed on the second and third whorls, 

 and incised spiral lines are well developed on the last whorl. 



The type lot of veatchii consists of smaller shells, pi. XV, figs. 6, 7, 

 in which the bands number 9 or 10, are brown or blackish and more 

 or less speckled. Fine, distinct granulation (as in levis) may be seen 

 •on the second and third whorls. The incised spirals of the last whorl 

 are weak and much interrupted. The lip is slightly expanded, the 

 •callus within making it appear more expanded than it really is. 

 This feature is rather poorly shown in the figures because of the 

 •darkness of the interiors in the photographs. In M. levis there is 

 little or no expansion of the lip. 



The largest individual seen measures, alt. 26|, diam. 28| mm. 

 It was collected by Hemphill (pi. XV, fig. 5). The highest in a 

 series sent by Mr. H. N. Lowe measures, alt. 2Q^, diam. 25| mm.j 

 with 6^ whorls (fig. 2) ; and the lowest, in the same lot, is, alt. 24^, 

 diam. 28 mm., 5f whorls (fig. 1). The types were smaller, about 

 23 X 23 mm. Two of the type lot are figured, pi. XV, figs. 6, 7. In 

 these the spiral incised lines are less developed than in the larger 

 forms. The lip is less broadly expanded in many specimens, as in 

 fig. 4, collected by Gabb. 



Besides the typical elevated form already noticed, there are several 

 more or less divergent forms found on Cerros Island. I have referred 

 to these by number, as their status cannot be discussed intelligently 

 until careful field work locates the colonies and gives material for a 

 study of the variations in each. 



(1) M. veatchii leucanthea Dall, from the eastern side of Cerros 

 Island (pi. XV, fig. 10, a cotype, U. S. Nat. Mus. No. 107,627) is 

 exactly like the lower forms of veatchii in shape of the shell and the 

 rather broadly expanded lip. It differs by the absence of distinct 

 bands on the pink-white surface and the more distinct granulation 

 of the entire upper surface. The shell figured measures, alt. 23, 

 diam. 26 mm., with 5| whorls. 



(2) Shells collected on Cerros Island by Hemphill, what part of 

 the island not stated, resemble leucanthea in shape and sculpture, but 

 differ in having the lip expansion very narrow. In one lot (pi. XV, 

 figs. 15, 16) the fleshy-brown bands vary from weak and "curdled" 

 (like the traces of a band in leucanthea) to moderately strong. 



(3) In another lot (pi. XV, figs. 13, 14) the last whorl has a pale 

 brown tint; there are no bands whatever, but the surface is strewn 

 with purplish-gray dots, translucent by transmitted light. The 

 lip expands very narrowly. 



