88 



CONTRIBUTION TO THE PALEONTOLOGY OF TRINIDAD 





Locality 



Rio Maria Farinha beds, State of Pernambuco, Brazil 



Geological horizon.— Midway Eocene. Equivalent to the Midway of Alabama 

 and of the No. 2 bed of Soldado Rock, Gulf of Paria. 



Calyptraphorus velatus Conrad var. compressus Aldrich. Plate XII, Figures 8, 9, 10. 



Anchura White, U. S. Geol. Surv., Bull. No. 4, p. 17, 1884. 



Roslellaria velata Aldrich, Geol. Surv. Alabama, Bull. No. 1, p. 59, 1886. 



RosteUaria Smith and Johnson, U. S. Geol. Surv., Bull. No. 43, p. 66, 1887. 



Calyptraphorus velatus Harris, Geol. Surv. Arkansas, vol. II, p. 46, 1892. 



RosteUaria (C.) velatus var. compressa Aldrich, Geol. Surv. Alabama, p. 244, pi. 12, figs. 2, 2a, 2b, 



1894. 

 Calyptraphorus velatus var. compressa Harris, Bull. Amer. Paleont., vol. I, p. 218, pi. 10, figs. 



7a, b, 8, 1896. 



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Aldrich' s original description of the variety. — "This form is intermediate be- 

 tween R. trinodifera Con. and R. velata Con. The adult has the enamel on the 

 front part as in R. trinodifera, but on the opposite side the line of demarkation 

 of the enamel comes down only to the (body) whorl. The specimens are also 

 much smaller than the normal adult. A similar form that cannot be separated 

 from this variety is common in the Matthew's Landing group, but is nearly twice 

 as large, and more rotund than those figured. The figures given are somewhat 

 larger than the type. 



Remarks. — Professor Harris has found this variety in the Midway of Texas, 

 Arkansas, Tennessee, Mississippi, Alabama and Georgia. He says 69 " The smaller 

 type of this variety is common in the lower and medial Midway beds. It is 

 one of the first to appear above the Eocene-Cretaceous contact line. The larger 

 specimens differ from the Calyptraphorus velatus from the Claiborne sand mainly 

 by the pointed exterior-posterior termination of the labrum; in velatus this por- 

 tion of the labrum is rounded, as shown by figure 5, Plate 15, of Conrad's Fossil 

 Shells, etc., 1835." 



In view of the wide distribution of this variety in the Midway horizons of 

 the southern states of North America— it is exceedingly interesting to find that 

 it is a common shell at Soldado Rock, Bed No. 2. It occurs in it with masses of 

 Cucullwa harttii, Turritella mortoni, T. nerinexa, Venericardia planicosta and a 

 mass of moulds and fragments of other species forming a veritable shell breccia 

 like the modern coquina rock. 



One specimen of the Calyptraphorus fortunately shows the sharply pointed 

 posterior termination of the labrum which differentiates this variety. The shells 

 are the small early Midway type, the fragments measuring about 25 by 14 mm. 



Locality.— Bed No. 2, Soldado Rock, near the Serpent's Mouth, Gulf of Paria. 



Geological horizon.— Midway Eocene. Equivalent to the Midway of Alabama 

 and of the Rio Maria Farinha beds, State of Pernambuco, Brazil. 



•• Bull. Am. Pal., I, p. 218, 1896. 



