Rathbun.] 36 [May 15, 



Comni., 1876.) This species was also found by Mr. A. Agassiz, asso- 

 ciated with Vilullna pustulosa, in Devonian deposits on the island of 

 Coati, Lake Titicaca, Bolivia. 

 Vitulina pustulosa Ilall. 



Vilulina pusiulosa Hall, 13th Rep. St. Cab. N. Y., p. 82, 1860; Pa- 

 Iseont. of N. Y., iv, p. 410, 18G7 ; llatlibun, Bidl. Bull'. Soc. Nat. Sci., 

 I, no. 4, p. 255, pi. ix, 1874. 



This species is very abundant in the sandstone beds of Erere and 

 the Rio Mascurii, and the specimens from these two localities agree 

 quite closely with one another in all their variations. A slender sep- 

 tum is often preserved in the ventral valves fi'om the Majcurii, and 

 specimens from this locality often have more prominent plications 

 than those from Erere. Only a few very snudl specimens were found 

 on the Rio Cm-ua. 



Erere. (Morgan Exs., 1870 and '71; Geol. Comm., 1870.) Rios 

 Maecurii and Curua. (Geol. Comm., 1876.) 



COXCLUSIOXS. 



To aid in comparing the founje of the three Amazonian Devonian 

 ocalities, there is given in the following table a list of the species de- 

 scribed in the preceding pages, with the locality or localities at 

 which each was found. 



By reference to this list it will be seen, that of the twenty- 

 one species recorded from the Mascurii, thirteen were also found on 

 the Curua, all the commoner species of the former locality, excepting 

 Spirifera duodenaria (?), being represented at the latter place. The 

 relationship existing between the Erere fauna and the Majcurii is 

 not so close. No Lingulaj were obtained on the Maecurii, though 

 two species were found in the Erere sandstone. Chonetes Comstockii, 

 so abundant, and often of large size, at Erere, is rare on the Majcu- 

 rii, and C. Herbert- Smithii is not found there at all. Spirifera Ped- 

 roana, Relzia Jamesiana and R. Wardiana, all abundant at Erere, 

 are very sparingly represented on the Maecurii. 



On the other hand the common Maecurii species, OrlJiis Harttii, 

 Strophodonla perplana, Spirifera duodenaria (?) and Amphigenia elon- 

 gata do not occur at Erere; and there are several types of Spirifera 

 and a Productella confined to the Maecurii beds. Chonetes Freitasii 

 Orthis Neltoana, Rhynchonella dolis and TrojyidoJeptus carinatus are 

 very abundant in the Msecuni beds, but in the collection from Erere 

 they are represented by only a few specimens each. Streptorhynclmi 



