THE NAUTILUS. Il7 



istome very heavily calloused within, the callus orange ; face of the 

 lip convex, thickened, a little expanded ; columella arcuate, reflexed, 

 having a strong fold above the middle, produced by a strong cres- 

 centic ridge which encircles the columella immediately behind the 

 reflexed columellar lip. There is a shallow^ peripheral sulcus upon 

 the latter third of the body-whorl. 



Alt. 29, diam, 14? mill.; alt. of aperture 16ii, width 10 mill., 

 inclusive of peristome. 



Habitat, New Hebrides. 



This species was sent to me by Dr. J. C. Cox of Sydney, N. S. AY. 

 Australia. It seems to be quite distinct from any of the described 

 forms. In some characters it resembles the genus Diplomorpha, 

 and Dr. Cox suggests that it may belong to that group ; but the 

 balance of characters seem to me in favor of Placostyhis. 



Dr. Cox writes " I have only recently received this, to me, quite a 

 new species of shell, and fancy it belongs rather to the genus Diplo- 

 morpha than to BuliviHS. I have one specimen with a thin brown 

 epidermis on it, another with the mouth quite pale colored." 



NOTES ON THE HELICES OF THE BIOLOGIA CENTRALI-AMERICANA. 



BY H. A. PILSBRY. 



Dr. von Marten's work on the land shells of Middle America, 

 now in course of publication in Godman and 8alvin's magnificent 

 work, Biologia Centrali-Americana, promises to rank as one of the 

 great faunal works of our time. Coming after Crosse and Fischer's 

 elaborate and beautiful volume, it is npturally more complete, and 

 to a great degree supplements the work of the French authors. 



The last parts of the Biologia issued contain a portion of the 

 account of the Helices, and as a resume of the principal points of 

 classification will be of interest to specialists, the writer has ventured 

 to briefly pass them in review. 



V. Martens recognizes Patula as a genus, and in it he includes 

 the sections Thysanophora and Microconus. 



In the genus Helix the following subgenera are adopted : 

 Acanthinula, Vallonia, Trichodisciua, Practicolella, Arionta, Pom- 

 atia, Lysinoe, Oxychona, and Solaropsis. In the subgenus Acan- 

 thinula are included the minute, conical-globose, narrowly unibil- 

 icated forms for which the writer some years ago proposed the name 

 Ptyehopahda. These forms seem to me to be nothing more than nar- 



