INSTITUTE OF SCIENCE, PHILADELPHIA. I4I 



Murex (Chicoreus ?) micromeris n. s. 

 Plate 12, figure 12. 



Rare in the Caloosahatchie Pliocene. Living in the Antilles (Jamaica 

 and St. Thomas, U. S. Fish Com.). 



Shell small, compact, with one and a half smooth nuclear and four sub- 

 sequent sculptured whorls ; transverse sculpture of (on the last whorl eight) 

 rounded ribs continuous over the shell, with wider interspaces, and by incre- 

 mental lines of which the edges are sometimes squamose, especially on the 

 spirals ; spiral sculpture of strong, elevated, granulose or slightly scaly 

 threads with equal interspaces, strongest near the periphery and weaker in 

 front of the suture ; these number from three to six on the earlier whorls 

 and on the last whorl are increased by intercalation ; canal short, almost closed 

 in front, with prominently squamose fasciole ; aperture subcircular, with a thin, 

 raised margin, smooth-edged on the inner or pillar-lip, crenulated by the 

 sculpture and internally lirate on the opposite side; suture distinct, not chan- 

 nelled ; Max. Ion. of shell 7.5 ; max. diam. 4.5 mm. 



The recent specimens are pink, or yellowish pink, and those that I have 

 are slightly more slender than the single fossil specimen. I had regarded 

 these as the young of Murex riifits, but having obtained a series of the latter, 

 it was evident that this was erroneous. 



There is a tendency on the earlier whorls toward a peripheral gap or 

 wider interspace between the spirals in which, on the last whorl, an intercalary 

 thread appears. 



Murex (Chicoreus?) Burnsii Whitfield. 



M. shilohensis Heilprin, var. .5?/r«in Whitfield (MS.), Miocene Gastr. N. Jersey, pi. 17, 

 fig. 2. 



Miocene marls of New Jersey, near Shiloh, and the Tampa silex-beds at 

 Ballast Point, Tampa Bay, Florida. 



The original specimen o^ M. shilohensis is in bad condition and suspiciously 

 like Muricidea spiniilosa, as far as it retains any characters (cf. op. cit. pi. 17, 

 fig. i). The truncated specimen, upon which Prof. Whitfield has founded 

 his variety Burnsii, belongs, in my opinion, to a different species and subgenus. 

 A young but entire specimen from the silex-beds completes the diagnosis 

 sufficiently to confirm this view. It should be observed that so far as the 

 young shell is concerned (and also the New Jersey specimen, though less 

 markedly) it is the complete image of Miirex interserratus Sby. of the same 

 age. The last species is still living in the southeastern Antilles in deep water. 

 It is, of course, impossible to say how much M. , Btirnsii would, in the adult 

 state, differ from the living shell, and so it will be safest to leave the casein 

 abeyance, awaiting fuller material. 



