66 GASTROCOPTA. 



there were over 1000 examples. G. duncana was much more 

 abundant at the summit of the island than lower down, but 

 it was found also in the lowest lot taken, at about 500 feet. 



Nine of the specimens have no upper-palatal fold, though 

 apparently fully adult. This is a very distinct species. 



Gastrocopta munita (Reibisch). PI. 17, figs. 3-9. 



Vol. 24, pp. 96, 357. Originally described from Albemarle, 

 among bushes near the seashore (Th. Wolf), it was taken by 

 Ochsner near Tagus Cove and near Iguana Cove; on Nar- 

 borough at 50 feet ; Charles Island at 750 feet, and on Tower 

 Island. The Pinchot Expedition obtained it at Chatham 

 Island, from Wreck Bay to the lower edge of the grassy zone. 

 Charles Island at Black Beach, a mile inland. Barrington 

 Island. Daphne Island, near Indefatigable. Albemarle 

 Island in numerous places on the road from Villamil to San 

 Tomas, at a low elevation, and at Tagus Cove. Tower Island 

 around Darwin Bay. Often found in great abundance, in some 

 places associated with G. clausa. Several thousand specimens 

 collected by Pilsbry, 1929. 



This a variable species, in which extreme forms might be 

 considered distinct if there were not so many transitional 

 examples. There are three main forms: 



1. Corneous, ovate, typically with an interpalatal fold and 

 a subcolumellar callus ; about 2.4 x 1.2 mm. Typical G. munita 

 (PL 17, figs. 7, 8, 9). 



2. Brown, subcylindrie, often lacking an interpalatal fold 

 and subcolumellar callus ; length 2.4 to 3 mm. Forma hrunnea, 

 n.f. ; chiefly from Kicker's Rock, Daphne Island and Tagus 

 Cove, Albemarle (figs. 3-6). 



3. Brownish, subcylindrie, sometimes lacking an interpalatal 

 fold and subcolumellar callus ; small, length 2 to 2.2 mm. 



Albemarle Island. — On the lava plain back of Villamil and 

 along the trail inland to San Tomas, only the typical form of 

 munita was found, the shell stout, ovate, corneous, with white 

 aperture (PI. 17, figs. 7-9; length 2.4, diam. 1.2 mm). This 

 is rather more likely to be the type locality than Tagus Cove, 

 as the latter is a rather out-of-the-way place. 



