Modification of the Apex in Gastropod Mollusks. 693 



Family FASCIOLARIID^. 



Genus FASCIOL.ARIA Lamarck. 

 Fasciolaria gigaiitea Kiener. (Figs. 25, 26. ) 



Apex small, rounded, smooth, consisting of one and a-half 

 whorls, rapidly enlarging; the nodules appear on the first post- 

 nuclear whorl ; color dead white. The young shell when taken 

 from the egg-capsule (fig. 26) consists of one and a-half sper- 

 maceti-like whorls, the point of the first whorl being bent in and 

 buried in the coil of the first whorl. The young shell measures 

 about 4 mill, in length and is very broad. 



Fasciolaria tulipa Liune. 

 Fasciolaria distaus Linu6. 



The apices of these two species are like that of gigantea ; 

 tulipa has a dark purple, and distans a spermaceti-like apex. 

 When the animal leaves the egg there would seem to be no dif- 

 ference of specific importance, those characters being acquired 

 later. The post-nuclear whorls of both species are smooth and 

 shining. Those who find difficulty in separating these two 

 species, m.a,y easily do so by observing the heavy spiral callus 

 just beneath the point where the periphery meets the body whorl 

 in distans. This is absent in tulipa. 



Genus FULGIJR Montfort. 

 Fulgur pyrum Dillwyn. (Figs. 27, 28. ) 



The apex is very like that of Fasciolaria gigantea, and consists 

 of the same number of whorls. The post-nuclear whorls are 

 strongly shouldered and tubercular. The young shell just from 

 the egg capsule (fig. 28) shows a rounded apex and shouldered 

 second whorl, and the interior of the aperture (outer lip) is strongly 

 and deeply striate, the striations running as far into the aperture 

 as can be seen. The apex is white in color. Of a large number 

 examined, all show the characters expressed above. The apex in 

 the young is almost hidden by the coil of the second whorl. 



Fulgur perversus Linn6. (Figs. 29, 30.) 



Apex large, rounded, knob-shaped, smooth for the most part, 

 consisting of one and a-half whorls regulai^ly increasing in size. 

 The second whorl is nodulous and soon becomes decidedly 

 shouldered where it meets the first post-nuclear whorl. Color 



