North American Species of Zonites. etc. 355 



XXVIII.— On certain North American Species of Zonites, etc. 



BY W. G. BIXJtfEY. 

 (With Plates XIV and XV.) 



Read October 20th, 1879. 



Most of the following notes will serve as a supplement to 

 " Terrestrial Mollusks and Shells of the United States," vol. V. 

 The balance are furnished from specimens lately collected at 

 Cape Town, South Africa, by Mr. J. S. Gibbons. 



Spiraxis (Euspiraxis) Dunkeri, Pfr. 



San Domingo, Mr. J. S. Gibbons. 

 No central teeth. (PI. XV, Fig. X). 



Glandina. 



Mexico. Dr. Edward Palmer. 



On pi. XIV, fig. L, I have figured the lingual dentition. There 

 are about 32-1-32 teeth. The centrals are narrow, with a very 

 slender cutting point. 



Rliylida vernicosa, Krauss. 



Cape Town, South Africa. Mr. J. S. Gibbons. 



This species is placed by Von Martens in Pella, a subgenus 

 of Helix. On examining the animal, however, I find it has no 

 jaw, and that its lingual membrane presents the usual characters 

 of Rhytida. Mr. Gibbons informs me ' ' that the animal wants 

 the characteristic labial palpi of the latter genus." There ap- 

 pears no central tooth. The rows of teeth are close together, not 

 widely separated. There are about 14-14 teeth (PL XIV, Fig. I). 



Slcnopu§? decolorants. 



Demerara. Mr. J. S. Gibbons. 



This species is allied to Zonites Oayennensis, Pfr., of Cayenne, 

 a species placed by Von Martens in Mesomphix. An examina- 

 tion of the jaw and lingual dentition leads me to consider it a 

 Stenopus (see Morse, Ann. X. Y. Lye, viii, 158, fig. 3). I 



