. The Conchologists' exchange. Mollusks. THE NAUTILUS. 139 Buccinum undatum^ by Morse, in Crepidula'^ by Conklin, in Rissoa aculeus^ and Littorina littorea*' by/Jeffreys, and in Fulgur carica by Burnett Smith.^ As far as I can find out, no one has reported it in Stromhus pugilis. The material was collected to determine if the variety alaius was but a case of sexual dimorphism, and if not was there any such dif- ference. 1 collected most of the individuals after a severe "norther'* in the latter part of January which had cast them up in moderate numbers on the beach of Sand Key near Clearw
. The Conchologists' exchange. Mollusks. THE NAUTILUS. 139 Buccinum undatum^ by Morse, in Crepidula'^ by Conklin, in Rissoa aculeus^ and Littorina littorea*' by/Jeffreys, and in Fulgur carica by Burnett Smith.^ As far as I can find out, no one has reported it in Stromhus pugilis. The material was collected to determine if the variety alaius was but a case of sexual dimorphism, and if not was there any such dif- ference. 1 collected most of the individuals after a severe "norther'* in the latter part of January which had cast them up in moderate numbers on the beach of Sand Key near Clearwater Harbor, Florida. Of those I examined, nineteen were males and nine were females. The variety alatus differs from the type in that it lacks the char- acteristic tubercles on the body whorl. Forty-four per cent of the females and twenty-six per cent of the males showed a tendency to be smooth. Of these observations and the ones to follow, the probable error is so very large, on account of the small number of individuals at hand, that only w^here the differ- ences are pronounced, are the results of value. On the material at hand I made the following measurements;-(Fig. 1) the length AB, the width CE, the angle at the apex, the columellar angle, and the aperture FG. On account of the ornamentation of the shell, the width CE and the apical angle were found to be so variable as not to be favorable for compar- ison. The ratio of AB to FG was in the case of females larger than in the case of the males. If this be true, and I have too few individuals to be sure of it absolutely, a very interesting feature is shown. The ^E. S. Morse, 1876, Proc. Boston Society of Nat. Hist., Vol. XVIII. 2E. G. Conklin, Jour, of Morphology, 1897, Vol. XIII., No. 1. 3 Jeffreys, British Conchology, Vol. IV., p. 38. ^Ibid., Vol. III., p. 343. 5 Burnett Smith, 1902, Proc. Acad. Natural Science of Phila., Vol. LIV., p. 507. Fig. Please note that these images are extracted from scanned page images that
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectmollusks, bookyear188
