cial in character.
It is not clearly evident, however, that we are dealing with exactly contemporaneous assemblages when comparison is made between the Angels Peak faunule and the rest of the San Juan fauna which serves collectively to define the typical Torrejonian. It may be: (1) that the Angels Peak faunule is of slightly different age than the latter, or (2) that the latter is susceptible of stratigraphic subdivision, and the Angels Peak faunule marks one stage of a sequence in time. This problem will not be easily solved, and perhaps may never be, for concentrations similar to that of the Angels Peak faunule are of infrequent occurrence. It is beyond the scope of the present paper, and of the present stage of our knowledge of the "Torrejon" fauna, to discuss at length the possible difference in age, but the following remarks summarize the matter for the Angels Peak material.
Many of the Angels Peak specimens differ in minor ways from those previously described from the Torrejonian of the Sa