Occasional Papers of the Museum of Zoology 3 



Although most of the specimens possess the typical, internal 

 callus, none have developed the teeth. 



PHVSID.E 

 Physa spiculata ]\Iorelet. Seven specimens ; from pools in 

 lowland forests (H, v, a) and in the burnt-over region (H, v, 

 b), and from roots of water-plants (Pistia) along the shore of 

 Laguna de Catemaco (H, vii, d), 



AXCYLID^ 

 Uiicancylus sp. ? Several specimens that appear to belong 

 to this genus were found on rocks, etc., near shore of Laguna 

 de Catemaco (H, vii, d). They have been sent to Dr. Bryant 

 Walker for examination. 



PUPILLID.E 

 Stcrkia hakcrl Pilsbry (1921). One specimen, the type, 

 from ground in lowland forests (H, i, a). 



Pupisonia dioscoricola insignc Pilsbry. Twenty-three speci- 

 mens ; from leaves of trees in lowland forests (H, i, b) and 

 the savannah brush (H, iii, b). (Identified by Dr. Pilsbry.) 



SUCCINEID.E 

 Succiiica z'irgata von Martens. One adult and 4 young 

 specimens ; on floating debris in Arroyo Hueyapam, near mouth 

 of La Laja (H, vii, a). The adult measures: 



Altitude Greatest diameter Height aperture Diameter aperture 

 12.3mm. 59(7.3mm.)i 67(8.3mm.)i 47(5.8mm.)i 



From the description and figures, I cannot separate this 

 species from the more southern S. guatcinalcusis ^Nlorelet, 



^ As in the previous parts of this paper, the first dimension is 

 given in millimeters, while the remainder are each expressed, as a 

 percentage, in terms of the first ; these ratios are followed by the 

 actual measurements in millimeters (in parentheses). 



