16 THE NAUTILUS. 



gukms, and thus proves to be a Gastrodoiita. The shell is thin, 

 transparent, somewhat greenish deep horn colored, of the same 

 appearance as Z. nitidus MiilL, which species it surprisingly resem- 

 bles below, while above it appears different by the greater number of 

 whorls. It seems that here we have a " missing " or connecting link 

 between the so-called type of Zonitoides, and its more characteristic 

 North American members. 



7. Mrs. Andrews has, of late, again sent me numerous small 

 Zonitidae, collected in the mountains of Tennessee and North Caro- 

 lina. From these I learned, beside other things, that Zon. andrewsi 

 W. G. B., when adult, has very often (or always ?) no internal teeth 

 at all. Moreover, the shell attains quite a different configuration : 

 the last whorl is placed considerably deeper on the penultimate, or 

 gradually descends, thus causing the spire to be much more ele- 

 vated ; it becomes also deeper and at last somewhat truncate in the 

 periphery (perpendicular section) and subangular below, compara- 

 tively large, just as we find it in some ligerus, gularis, svppressus. 

 At the same time, the base is no more equally rounded, but becomes 

 sloping inward, somewhat infundibuliform, the umbilicus is rather 

 large, and the striation becomes more crowded and coarse, even so 

 that the strife appear to be raised (t. e. the intervals) in place of 

 impressed, as they are on the inner whorls. The whole shell then has 

 quite a different appearance from that commonly known as Z. 

 andrewsi, much resembling the description and figure oi Zon. placen- 

 tuhis Shuttl. (in W. G. Binney's Manual, p. 222). The whorls are 

 fully 9 or more, the diameter 7-7'5 mill. It was somewhat difficult 

 to state these relations, as I had, though, a good number of speci- 

 mens, no complete series from one locality at disposition. There is 

 no doubt, to say no more, that many such examples have been 

 taken for Zon. placentuhis. And, as a striking proof of this, I have 

 in my collection four specimens from the mountains of North Caro- 

 lina I'eceived as Zon. placenhilu?, years ago, from a conchologist who 

 studied those land shells ; they show more or less the characteristic 

 features noted above, and one of them has a distinct row of denti- 

 cles denoting it unmistakably as Zon. andrewsi. 



8. As with the preceding, it is with Zon. dgnificans Bid. Only the 

 younger examples, i. e., those commonly found in collections under 

 this name, have the teeth, two series of two, as a rule. In older 

 specimens, of 5-6 mill, diam., they are no more formed, or only 

 occasionally one or another, and then the shells have the characters 



