Occasional Papers of the Museum of Zoology 39 
Altitude Greatest diameter Heightaperture Diameter aperture 
32.2 mm. QI (29.3 mm.) 72 (24.8 mm.) 53 (17.1 mm.) 
24.6 mm. QI (22.4 mm.) 78 (19.2 mm.) 52 (12.8 mm.) 
Ampullaria patula Reeve (1856),' catemacensis, new 
subspecies 
Figs. 2, 3, 4 and 7 
Twenty-five specimens from Lake Catemaco (H, vii, d). 
Shell thin, translucent, rimate; ground-color yellowish to 
olive-green or dark brown (rich amber by transmitted light), 
with 25 to 40 darker brown, spiral bands or lines of varying 
widths, sometimes with a broadish band of creamy yellow 
just below suture; surface marked with fine growth-wrinkles, 
crossed by regularly spaced, delicate, more or less beaded 
wrinkles, 2 to 3 mm. apart, and by microscopic, wavy ridge- 
lets, so as to give the shell a beaded appearance under the lens ; 
spire very low (somewhat eroded and pitted at very tip); 
whorls 4 or 5, rapidly expanding, more or less flattened above, 
_each with the sutural edge sloping up over the preceding whorl 
so as to give, with the sharply marked, somewhat undulate 
suture, the impression of being flattened over it; last whorl 
greatly inflated, so as often to about equal in diameter, as 
viewed from above, all of the others combined; aperture very 
large; peristome slightly thickened within, but with edge 
1Dr. Bryant Walker, to whom I sent the accompanying figures of 
this form, writes: “Your figure certainly looks very much like Reeve’s 
patula. Curiously enough, Sowerby in his recent revision of Ampul- 
laria (Pr. Mal. Soc., VIII, p. 345) seems to have omitted any refer- 
ence to it. I have four lots in the collection labelled ‘patula’ One 
from the Amazon has got misplaced and I have not been able to find 
it. The other three evidently belong to the same species, whatever it 
may be. One lot from ‘Brazil’ are dealer’s specimens, and I know 
nothing of their history. The other two came from New Granada. 
They come from Rolle. The ‘typical’ form is banded and has the 
interior dark brown, but the aperture is not so expanded as in your 
shells, and the apex is higher than in Reeve’s figure. The largest 
specimen measures 30.5x25 mm.; tip of apex eroded.” 
