MUSEUM OF COMPARATIVE ZOOLOGY. 311 



whorls, and tlio, varicoi^ aro more orect and lamellar, and the suture less dis- 

 tinct, than in .S'. multUtriala of tlie same lengtli. The fasciole is quite absent 

 in the last mentioned loini, l)nt they both agree in having more varices and 

 stronger striie on the early whorls than on later ones. 



Scala modesta Adams. 

 Scala modesta C. B. Adams, Proc. Best. See. Nat. Hist, II. p. 7, 1845. 



The shell described by Mbrch (Journ. Acad. Nat. Sci., VIII. p. 203, 187G) 

 under this name, and serving as the type of his subgenus lanthoscala, is not 

 the shell described by Prof. Adams, as a comparison of diagnoses shows at 

 once. S. modesta, from the author's types, is solid, white, with eleven continu- 

 ous varices, and is engraved, all over with fine sharp spiral stria3, which even 

 ascend the varices. Morch's shell is smooth and has twenty-one varices, and, 

 as I do not find any name for it, may be called S. permodesta. S. modesta is 

 well distinguished from S. centiquadra Morch by the absence of decussation in 

 the fine sculpture, and by its much stouter build and stronger varices of trian- 

 gular rather than lamellar section. It has no resemblance to S. venosa Sby., 

 but S. undecimcostata Morch is very likely a synonym of modesta. 



Scala clathrus Linne. 



Scala clathrus Linne, Syst. Nat., ed. xii., p. 1237. {S. lamellosa Jjum. pro parte, Morch, 

 Scalidce, loc. cit., p. 199.) 



I am entirely in accord with ^Morch as to the propriety of separating the 

 West Indian shell from S, lamellosa (= S. commutata Mts.) of the Mediterra- 

 nean. With a fine series of both, before me, I can find no approach to the 

 transition spoken of by Mr. Tryon in his Manual. The two forms are as dis- 

 tinguishable as the vast majority of species, and would very likely be put in 

 two "genera" by the so called "new school" conchologists; not that this, 

 however, would form much of an argument. 



As the only clathrus of Linne which can be identified is the present species, 

 it would seem as if his name should be retained for it, otherwise it must have 

 a new one, the available synonyms all referring to the Mediterranean form. 



Scala babylonia n. s. 



Shell thin, white, elongate, with fifteen rounded whorls (nucleus lost) each 

 ornamented with about twenty-five thin sharp varices each of which has a 

 small triangular sharj) point half-way from the suture to the periphery; behind 

 these the interspaces are smooth to the suture ; in front of the varical points 

 the surface is sculptured with raised flat-topped threads with wider intervals 

 between them and numerous still finer spiral striae; the spiral sculpture does 



