MUSEUM OF COMPARATIVE ZOOLOGY. 281 



which I have given the above name. Since seeing it I am led to suspect 

 that d'Orbigny's P. bolieiensis is the same species, though his figures repre- 

 sent a very different shell, with some characters probably never seen on a 

 species of this genus. De Koninck's figures are much more like our shell, 

 though, if strictly accurate, the two would appear to be distinct. Aside from 

 some differences in form, the front of the shell in his figures is quite strongly 

 ribbed, while among hundreds of specimens from Brazil it is uniformly 

 smooth. The differences are sufficiently important to warrant the retention 

 of my name till the original types of P. boliviensis can be examined. 



Productus Cora d'Orbigny. 



Productus Cora d'Orbigny (op. fit.), p. 55, PL V. Fig. 8-10. 



There are several fragments on a slab from Yampopata which most proba- 

 bly belong to this species, the type of which was from the neighboring 

 locality of Yarbichambi. It is unfortunate that we have no really good 

 specimens from Bolivian localities to show clearly the characters of the 

 species. D'Orbigny's figures of it are useless for purposes of identification, 

 and Toula, who had specimens from Cochabamba, thinks that the European 

 specimens figured under the name by De Koninck, and which are now re- 

 ferred to as the type of the species, are distinct. If it should prove so, a 

 thorough revision of the peculiar group of Producti to which this belongs 

 will be necessary. 



The Brazilian forms referred with a question to this species are appar- 

 ently identical with those collected by Mr. Agassiz. 



Euomphalus antiquus d'Orbigny. 



Solarium antiquum d'Orbigny (op. cit.), p. 42, PI. III. Fig. 1-3. 



The specimens referred here are in the state of partial casts, occurring 

 both at Yampopata and the island of Titicaca. They agree in the most 

 essential particulars with d'Orbigny's type, though differing somewhat from 

 his figures and from each other in the prominence of the spire, the form of 

 the whorls, and # the development of the thin carinas characteristic of the 

 species. It is possible that these differences may prove to be of specific im- 

 portance when larger collections are examined. 



This species is named by Meek as one of the types of his subgenus Ompha- 

 lotrochus proposed in the Geol. Surv. of California, Vol. II. p. 16. 



Euomphalus sp. 

 A cast of a species of Euomphalus with more angular whorls than the pre- 

 ceding and apparently with only a median carina occurs in the collection 

 from Yampopata, associated with a fragment of a much larger species with 

 smooth evenly rounded whorls. 



