STROBILOPS, MEXICO, CENTRAL AMERICA. 33 



long, as in S. streheli. The color of shell and lip is cinnamon 

 in the type lot, all dead shells, but chestnut brown in the fresh 

 shells from Necaxa. The glossy base is largely smoothish, the 

 last third ribbed more or less. 



Height 1.8, diam. 2.7 mm. ; 5% whorls. Type. 



Height 1.95, diam. 2.75 mm. ; Si/o whorls. Necaxa. 



Height 1.8, diam. 2.6 mm. Necaxa. 



Eastern and northeastern Mexico: Diente, near Monterey, 

 Nuevo Leon (type loc. ; S. N. Rhoads, 1899) . Around Necaxa, 

 northern Puebla (H. Burrington Baker, 1926). 



This form appears to be abundant in both of the localities 

 known, which are in a higher zone than that inhabited by S. 

 streheli. I have separated it from S. cunea with some doubt, 

 as the difference is slight, but the umbilicus in cenea seems 

 always to be a little smaller, the color of fresh shells is dif- 

 ferent, and adult individuals of cenea from the United States 

 generally have four basal folds. 



5. Strobilops strebeli (Pfr.). PI. 5, figs. 1-4. 



"Shell perforate, depressed-conoid, closely costulate above, 

 brown ; spire convexly conoidal. Whorls 5I/2, a little convex, 

 slowly increasing, the last not descending, with a crenulate, 

 subcarinate periphery, nearly smooth below the angle. Aper- 

 ture oblique, ear-shaped, furnished with two parietal lamellse 

 (the outer one reaching forward, the other more deeply 

 placed) ; peristome simple, the upper margin straight, the 

 basal a little reflected towards the insertion. Greater diam. 

 22/3, lesser 21/0, height II/2 mm." (Pfr.). 



Helix streheli Pfeipfer, Malak. Blatter VIII, 1862, p. 71, 

 pi. 1, f . 5-8 ; Monographia Hel. Viv. V, p. 222.— Strohila laby- 

 rinthica Say (specimens from Mirador), Strebel, Beitrag 

 Mex. Land- und Siisswasser-Conch. IV, 1880, p. 43, pi. 4, f. 6 

 (only) ; pi. 15 fig. 7 ?. — Von Martens, Biologia Centr. Amer., 

 Moll., 1892, p. 173. 



Mirador specimens, which are doubtless part of the original 

 lot, are drawn in pi. 5, figs. 1 to 4. They agree fully with 

 three examples, 14554 Strebel collection, coll. by Berendt, 

 kindly lent by the Zoologische Staatsinstitut und Zoologische 

 Museum, Hamburg. Two of these measure : 



