CERION, GROUP II. 189 



Form perplexum Maynard. (PI. 27, fig. 1G.) Form and size of 

 copia, or with the cone of the spire longer, approaching acutum. 

 Pinkish or bluish white, sometimes indistinctly maculate with fleshy 

 above; the aperture brown, peristome strongly thickened and tinted. 

 Terminal cone rather regularly and finely ribbed, but on the cylin- 

 drical portion the riblets are small and low, irregularly developed and 

 widely, unevenly spaced, becoming stronger on the latter half of the 

 last whorl. Whorls 10-11. Length 22.5, diam. 10 (type), but 

 varying from 25 to 19.5 mill. long. 



This form differs from intermedium and copia by its more or less 

 subobsolete riblets. In acutum the spire is more tapering and acute. 

 Maynard writes that perplexum occurs on the island of Cayman Brae, 

 in a " barren rocky section, about two miles from the west end of the 

 Key, and a quarter of a mile from the south shore. They were re- 

 stricted to a very limited area, and 1 found them clinging to low 

 herbage or to the naked rock, in almost every instance exposed to 

 the burning rays of a tropical sun." 



Form glaber Maynard. (PI. 27, figs. 17, 18.) Much smaller 

 than form perplexum, but like it in having the terminal cone costel- 

 late and the cylindrical portion nearly smooth, or witii only low, 

 irregular subobsolete riblets. Bluish-white, with abraded patches of 

 brownish or purplish-brown. Whorls 9 to nearly 10. Peristome 

 thick, pale. Length 15.5, diam. 8.2 ; length 16.2, diam. 7.5 mill.; 

 varying from 22 to 15 mill. long. This is merely a colony of dwarf 

 perplexum, just as parvum is dwarf copia. Sixteen specimens were 

 taken. Maynard writes: "I found this species very rare on the 

 margin of the path near the area occupied by S. parva (on the west 

 end of Cayman Brae near the northern terminus of the path that 

 crosses the key near the houses). They were rather solitary in 

 habit, and occurred on the low herbage which offered them an 

 opportunity for concealment." 



C. LEVIGATUM Maynard. PI. 27, figs. 19, 20. 



Shell perforate and rimate, oblong-cylindric, strong and solid ; 

 whitish, more or less stained with blue or livid flesh-color; whorls 

 10-11, flat. Nepionic shell of 2^ whorls, the first H smooth, next 

 whorl narrower, finely striate ; the succeeding ivhorl (first post-nepionic 

 whorl) ribbed. The rest of the whorls, except the last, are nearly 

 ^smooth, marked by slight wrinkles and occasional faint indications of 



