1909.] NATURAL SCIENCES OF PHILADELPHIA. 369 



NOTE ON THE MORPHOLOGY OF FULGUR. 



BY BURNETT SMITH. 



On the whole the marine gastropods are singularly free from indi- 

 vidual abnormalities or deformations, and this rule holds good for 

 the two large conchs (Fulgur carica Gmelin and F. canaliculatum 

 Say) which are washed upon our Atlantic Coast in such large numbers 

 during the winter storms. As far as the writer knows there is no record 

 of an abnormal individual of F. carica. F. canaliculatum, on the 

 other hand, has furnished a small number of deformed specimens 

 which have found their way into museums. Some of these have been 

 described and figured. 



Deformations of the Shell in F. canaliculatum. — In the museum of 

 the Academy of Natural Sciences of Philadelphia there are two ab- 

 normal shells of this species. In the first of these the branchial 

 siphon has grown in such a way that its direction is almost at right 

 angles to the axis of coiling of the spire. From an examination of 

 the exterior of the shell it is impossible to state with certainty the 

 causes of this condition. Whether it is the result of accident or of 

 some truly pathologic condition cannot be determined. 1 The second 

 specimen, collected at Longport, New Jersey, was figured and de- 

 scribed by the present writer. 2 In this case the deformation can 

 be traced to a break in the shell which occurred at a relatively early 

 stage in the ontogeny. The result of this has been a complete change 

 in the whorl form and sculpture, the tubercles and shoulder keel 

 disappear and we have a smooth, rounded whorl very similar to that 

 of F. pyrum Dilw. In this connection- it is interesting to note that 

 paleontological data points to the descent of F. pyrum either from 

 F. canaliculatum or from some very closely allied form, and further- 

 more that this descent was marked by the almost complete disappear- 



1 "A Remarkable Monstrosity of Fulgur canaliculatum," C. W. Johnson and 

 H. A. Pilsbrv, The Nautilus, July, 1895, p. 25, fig. 1. 



2 Proc. Acad. Nat. Sci. Phila., June, 1902, p. 507, and April, 1905, p. 358, 

 PI. XXXI, fig. 10. 

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