NATURAL SCIENCES OF PHILADELPHIA. 145 



tint varies from nearly wliite or pale delicate j'ellow to briglit 

 salmon-color. 



Busycon carica, Linn. 



Abundant ; probably there are ten or more of this to one of the 

 last or of the next. They are used for food by the lower classes. 



This pyrula spawns in May. I have observed and taken nu- 

 merous specimens with the egg-case issuing from them. At this 

 season the females resort to the shoals covered with a foot or so 

 of water at high tide, and exposed at other times. They bury 

 themselves a few inches below the surface of the sand, and doubt- 

 less remain stationary during the whole process, which appears 

 to require considerable time (not ascertained, even approxi- 

 mately). The case is thrust upward through the sand, and at 

 length appears above the surface, lying exposed, and thus indicat- 

 ing the whereabouts of the animal. The string begins as a simple 

 shred of the substance, two or three inches long, without proper 

 cases. The first few cases are imperfect, smaller than the rest, and 

 of decidedly different shape ; one or more may not contain young 

 shells. They regularly increase in size, and assume with equal 

 regularity the perfect shape. The string is spun out to an average 

 length of between two and three feet ; the cases are largest and 

 most closely packed at or just beyond the middle; the series 

 generally terminates more abruptly than it began. 



These es^or-cases have the form of those ascribed to Pyrula 

 canaliculata by Mr. Smith (Ann. Lj'C. Nat. Hist. N. Y., vol. vii, 

 p. 150), and by Mr. Geo. H. Perkins (Proc. Bost. Soc. Nat. Hist., 

 vol. xiii, p. 115). Mr. Smith writes: "I have determined the 

 species to which each form of egg-cases belonged simply by com- 

 parison of the young shells contained in them with adult specimens 

 of P. carica and canaliculata; and have ascertained from Mr. 

 Perkins that he made his determination in the same way. I have 

 made a comparison of the young shells contained in the broad- 

 edsed cases comin£c from Fort Macon, with similar ones from 

 Rockaway, L. I., and find them to agree exactly. Mr. Perkins 

 and myself are therefore evidently wrong, the broad-edged cases 

 belonging to P. carica, and the sharp-edged to P. canaliculata.^^ 

 Egg-cases of the broad form are abundantly strewn on the beach 

 and elsewhere, especially during the summer months ; but I do 

 not now call to mind that I ever noticed the sharp-edged ones. 

 1871.] 



