14 STROBILOPS. 



appendix (ap) which is thickened at the base and in the distal 

 half. The penial retractor (pr) is bifurcate, one branch in- 

 serted at the summit of the penis (or on the epiphallus), the 

 other on the swollen basal part of the appendix; posteriorly 

 the retractor joins the right ocular muscle. The oviduct is 

 "thin-walled, slightly pouched." The spermatheca {sp) on a 

 duct of medium length without diverticulum. 



The animal is oviparous. 



The digestive tract is composed of the usual elements f 

 buccal mass, salivary glands, oesophagus, stomach and intes- 

 tine. Two features seem to be noteworthy. The oesophagus 

 is not a slender duct as usual, but the walls are "knotty" or 

 slightly convoluted throughout. Also on the stomach there 

 appears to be an accessory gland, closely appressed to the 

 walls of that organ. The salivary glands are united into one 

 but they seem to discharge into the buccal mass at the usual 

 two points. 



Type, S. labyrinthica (Say). 



Distribution : Humid eastern half of North America from 

 Quebec, Ontario and Manitoba, N. Lat. 52°, to Guatemala; 

 Cuba and Jamaica; South America from Venezuela, north- 

 eastern Brazil and the Galapagos Islands; Japan, Korea, 

 China and the Philippines. Eocene to Pliocene of central and 

 western Europe. 



Strohilops comprises small snails living on decaying logs 

 and dead leaves in moderately humid forest. The genus is 

 not known in America west of the 100th meridian, but east- 

 ward its distribution is probably almost continuous, from 

 James Bay in the north to Guatemala, although at present 

 there are few Mexican records. It has not been turned up in 

 Costa Rica or Panama, the best known Central American 

 faunas, but appears again in Venezuela, Para and the Gala- 

 pagos. These three remote localities in South America may 

 indicate a wide distribution in that continent, and perhaps 

 many species to be discovered. 



In eastern Asia species have been found in Uzen Province 

 of northern Nippon, in Korea and China, The peculiar sub- 

 genus Entcroplax is confined to the Philippines. 



