PLIOCENE ECHINODERMATA. 



Class ECHINOIDEA. 



Subclass REGULARIA ECTOBRANCHIATA. 



Order DIADEMOIDEA. 



Suborder ECHININA. 



Family STRONGYLOCENTROTTDiE. 



Genus STK.ONGYLOCENTB.OTTJS Brandt. 



Strongylocentrottjs drobachiensis (Miiller). 

 Plate XGIX, figures la-c. 



Description. — Two specimens have been examined from the Pliocene beds of Caloosahatchie 

 River that evidently belong to this common and widespread Recent species. The characters are 

 similar to those of living forms, and it seems therefore that the specimens must be regarded as 

 representing the same species. A. Agassiz 1 points out the great variability in the different 

 individuals of the species, forms much more extreme than those of the two Pliocene specimens 

 studied occurring. 



Dimensions. — Diameter 55 millimeters; height 27 millimeters. 



Locality. — Caloosahatchie River, Fla. 



Geologic horizon. — Pliocene. 



Collection. — Wagner Free Institute of Science (4350). 



Subclass IRREGULARIA. 



Order GNATHOSTOMATA. 



Suborder CLYPEASTRINA. 



Family SCUTELLID.E. 



Genus DENDRASTER Agassiz. 



Dendraster •interoneattjs (Stimpson). 



Plate C, figures 2a-b. 



Scutella interlineata Stimpson, 1856, Pacific Railroad Repts., vol. 5, pp. 153, 154. PI. IV, fig. 30. 



Scutella interlineata Hemond, 1863, California Acad. Nat. Sci. Proa, vol. 3, pp. 14, 15. 



Scutella interlineata (Blake) Meek, 1864, Smithsonian Misc. Coll., vol. 7 (183), p. 2. 



Scutella interlineata Gabb, 1869, Geol. Survey California Rept., Paleontology, vol. 2, p. 110. 



Scutella interlineata Cooper, 1888, Cat. California fossils: State Mineralogist Seventh Rept., p. 271. 



Scutella interlineata Merriam, 1899, California Acad. Nat. Sci. Proa, 3d ser., Geology, vol. 1, No. 5, p. 169, PI. XXII, 



fig. 6. 

 Dendraster (?) interlineatus Stefanini, 1911, Soc. geol. italiana Boll., vol. 30, p. 706. 



Description and determinative characters. — -The writer has been unable to secure for study 

 more than a few specimens of this species. Among these is Stimpson's type — a greatly weath- 

 ered and fragmentary specimen. As Merriam, on the other hand, has had considerable material 

 to work with, his description is here repeated : 



Test pentagonal to circular, angular or truncated posteriorly, somewhat arched above; summit nearly central and 

 in front of the excentric apical system, specimens ranging up to over 120 millimeters in diameter. 



1 Revision of the Echini, pp. 277-2S1. 



