20 



University of Michigan 



While these specimens vary considerahly in size, none are 

 as large as typical H. t. appnni (type locality given as Puertc; 

 Cabello). The undulation of the basal wall of the i)eristome. 



Figure 20. Hcliciiia {Tanisiaiia) laiiisiaiia. Centrals, laterals and 

 tip of 3rd uncinus. The scale indicates a length of 50 microns. 



which caused Wagner (1907) to include this group in Alcadia, 

 is seldom distinct, and usually very obscure. I have not seen 

 specimens of H. cohiwhiana Philippi ( 1847) from Colombia, 

 but .suspect that the larger H. sauctacnuvtiuic I'ilsl)ry and 

 Clapp (1902) from Libano. Santa Marta Mt;., Coloml)ia (1, 

 II, 74), is closely related. The last is more nearly conical than 



