. Carnegie Institution of Washington publication. 52 FOSSIL ECHINI OF THE WEST INDIES. Genus MELLITA Agassiz, 1841. Type species.—Scutella quinquefora Lamarck, 1816, Anim. sans Vert., vol. 3, p. 9 = Echinodiscus quinquiesperforatus Leske, 1778, Add. ad Klein, p. 133. Mellita species. (Text-figure 6.) The following is a description of this specimen: Test elliptical, a little longer than wide. Very small, low, thin, with rounded edges. The ambulacral petals are rounded and rather short. A small oval lunule is in interambulacrum 5, nearer to the posterior border of the test than it is to the apic
. Carnegie Institution of Washington publication. 52 FOSSIL ECHINI OF THE WEST INDIES. Genus MELLITA Agassiz, 1841. Type species.—Scutella quinquefora Lamarck, 1816, Anim. sans Vert., vol. 3, p. 9 = Echinodiscus quinquiesperforatus Leske, 1778, Add. ad Klein, p. 133. Mellita species. (Text-figure 6.) The following is a description of this specimen: Test elliptical, a little longer than wide. Very small, low, thin, with rounded edges. The ambulacral petals are rounded and rather short. A small oval lunule is in interambulacrum 5, nearer to the posterior border of the test than it is to the apical disk. There are slight emarginations in ambulacra I and V, which appear to be the beginnings of lunules formed by inclusion. The apical disk is central in position, but there are no genital pores visible, although the specimen is very well preserved. It would seem that the absence of the genital pores indicates the youth of the specimen. This specimen measures 7 mm. in length, 6 mm. in width, and about 1 mm. in height. Comparing this evidently young individual with material in the Museum of Comparative Zoology, it is almost identical in structure with very young specimens of Mellita sexiesperforata (Leske) of about the same size. It seems at first sight unreasonable to assume that the genus Mellita should be represented in the fossil state in the West Indies only by a specimen of such • , • J- • i i T>I i FIG. 6.—Mellila spe- ranty as a very young individual. Ihe only other des x about 4 reasonable view would be to assume that it is an adult, or at least relatively much older individual of a very small species. It would then be most primitive in structure, would not fit into the genus Mellita or any other genus at present known, and the absence of genital pores, which is only a youthful character in Echini, would not be accounted for other than by assuming rather extreme youth. Miocene, Mayo Village Quarry (locality 11), Trinidad, F. W. Penny collector, U.
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