622 PATAGONIAN EXPEDITIONS! ZOOLOGY. 



III. 



Middle American (Mexico-Antillean) Forms, of Later Date in South America 



than the Archhelenic Group, in Some Cases Generically Differentiated 



from their Northern Ancestors, but more often Belonging to the 



Same Genera ; Therefore Doubtless Traceable to both Earlier 



and Later Migrations Southward. 



Helicidce 1 (figs. 31, 32). Physida. 



Urocoptida (fig. 33). Cyclophoridce (fig. 34). 



Oleacinidce (fig. 30). Cyclostomatidce. 



Pupillidce. Proserpinidce. 



Feriissacidce. Helicinida. 



Lymnceidce (of the Galba group). 



These intrusive forms from middle America are characteristic of the 

 Guiana-Andean region, though a few have attained a wider distribution. 

 Streams of migration from and to the Antilles are indicated by the way of 



1 The belogonous and epiphallogonous Helicida of South America are clearly of northern 

 origin. Whether such extremely peculiar genera as Solaropsis, Psadara and Macrocyclis also 

 belong in the same category, seems somewhat uncertain, although such competent malacologists 

 as von Ihering and Fritz Wiegmann place these genera in the Epiphallogona. 



The heavy, large Helices of the Eocene of southern Europe, such as Deutellocaracolus, Pro- 

 thelidomus, Galactocheilus and Fridolinia, may perhaps belong to the group Epiphallogona of my 

 arrangement, rather than to the Helicinae where I formerly placed them ; yet if so, I think the 

 supposed relationship to West Indian forms is not especially close. Like the American and 

 European species of Adelopoma, the Epiphallogona probably reached both Europe and America 

 from eastern Asia, and from opposite directions. 



Dr. von Ihering (Verhandlungen k. k. zoologisch-botanischen Gesellschaft in Wien, LIX, 

 1909, pp. 420-428) has recently referred the belogonous Helices (Epiphragmophora) of Argen- 

 tina and southern Brazil to the European genus Helicigona (Campyliza auct.) ; but I do not 

 believe that this classification can be sustained. So far as I know, the South American Epiphrag- 

 mophoras have the spermathecal duct very short, whereas Helicigona, like all other European 

 Belogona, has a very long duct, bearing a long diverticulum, which is bound by a membrane to 

 the oviduct. These are important differences, quite sufficient to show that Epiphragmophora is 

 not at all closely related to Helicigona, aside from the different shape of the mucous glands, and 

 their removal in Epiphragmophora from the vagina, upon which they are invariably inserted in all 

 European Belogonous Helicida;. 



By its short spermatheca, Epiphragmophora differs strongly from all other known belogonous 

 Helicida. In other features it stands nearer to Antillean and North American forms than to 

 European. My former treatment of the genus was too inclusive. I would now restrict Epiphrag- 

 mophora to forms having the spermatheca short, removing all of the Mexican and North Amer- 

 ican species (which have a long spermathecal duct) from the genus. 



