ORTMANN I TERTIARY INVERTEBRATES. 
199 
1885 V. i. Zittel, Handb. Palseont., v. 2, p. 212, textf. 285. 
1900 V. cf. i. Ortmann, in: Amer. Journ. Sci., v. 10, p. 379. 
Shell generally gregarious, tubular, subquadrate, closely and regularly 
spiral in the young state, with the whorls in close contact. The extrem- 
ity suddenly reflected, straightened and free. Aperture subcircular. 
Surface transversely rugose and often with longitudinal ribs. 
Diameter of tubes in our specimens : 2 mm. 
Remarks : Our specimens are not well preserved and only fragmentary, 
but they agree in general form closely with the figure given by Hoernes. 
Longitudinal ribs are present at the suture, where the whorls touch each 
other, and further, there seems to be a single rib in the middle of the 
whorls, but this rib is visible only on the uppermost whorl of the figured 
specimen. In size (diameter), our specimens agree best with Wood’s 
figure 8a, and differ considerably from that of the Italian Pliocene form 
figured by Zittel. 
Record of specimens: Shell Gap, Rio Chico, upper horizon: 1 sp.; Lake 
Pueyrredon, 600' above base : 1 sp. 
Distribution : V. intortus is found in Oligocene, Miocene, and Pliocene 
deposits of Europe. 
Affinities : Our specimens agree best in the surface characters with the 
Central-European Miocene form figured by Hoernes, in size with the 
English Pliocene form figured by Wood, while the Italian Pliocene form 
is larger, and has more, and more distinct longitudinal ribs. According 
to Moerch’s diagnoses, it would correspond best to the French Miocene 
form ol this species. There remains, however, some doubt, whether we 
really have to deal here with this European species, but the material at 
hand is too incomplete to decide this question. 
129. VERMETUS (?) INCERTUS Sp. llOV. 
PI. XXXII, Fig. 2. 
Tubes fragmentary, elongate-cylindrical, very slightly and irregularly 
curved, almost straight. Walls thick. Outer surface transversely rugose, 
in one specimen indistinctly flattened on one side. 
Diameter of tube : 5-8 mm. 
Remarks: There is considerable doubt whether these tubes belong at 
all to Vermetus , and I cannot find any described species, with which to 
