22 THE NAUTILUS. 



cisely than has liitherto been done. As I have no longer time or 

 opportunity for this work, I venture to put .together the following 

 notes, on the chance of their proving useful to other students. The 

 genus is a most difficult one, and until someone will elaborately 

 monograph the American species as Baudon has the French ones, 

 we seem hardly likely to arrive at any satisfactory arrangement. 

 With regard to the opinions given below, it is to be understood that 

 they are nothing better than opinions, founded on the material 

 examined. Further study Avith more abundant material would very 

 likely cause some of them to be altered. 



The American species of Sacclnea may be divided into four sec- 

 tions, three of which have received subgeneric names. 



Sect. 1. Amphibince. 



= Amphihina (Htm.) Mc'irch. 



(1.) Suecinea pfeifferi ^o^im. Many of the American forms of 

 ovalis Gould are not to be separated from the European 

 pfeifferi, Avhile others, also hardly distinct from ovalis, might 

 in the absence of intermediates be supposed to represent a 

 peculiarly American species. The American forms of Suc- 

 cinea, both in this and other groups, are very closely allied, 

 but at the same time seem more constant in their slight 

 peculiarities than those of Europe. In Ann. and Mag. of 

 Nat. Hist., March, 1887, I referred ovalis to pfeifferi, and 

 nothing since has appeared to prove otherwise. 



(la.) S. pfeifferi vav. hrevis Pascal. This variety was originally 

 called hrevis, but afterwards unnecessarily changed by 

 Baudon to brevispiraia, because there is a S. brevis in Central 

 America. I received a characteristic specimen, collected by 

 Mr. D, B. Cockerell at Toronto, Canada. In shape, this 

 variety is very like S. higginsi, and probably the two will be 

 found to intergrade. 



(2.) S. higginsi Bland. Probably a variety or subspecies of pfeif 

 feri, but a specimen marked higginsi, which I saw in the 

 Binney and Bland Collection, at the American Museum of 

 Natural History,' seemed to have affinity with S. elegans, 

 Avhile another in the same collection resembled pfeifferi very 

 closely. 



^ I was much indebted to Mr. Sanderson Smith for his kindness in showing 

 me this collection when I was in New York. 



