Neptuneidae and Fasciolariidae 167 



where the mollusks are abundant. 



The subspecies and variants most important to students inter- 

 ested in west Florida types are M. corona inspinata Richards, which 

 has square shoulders without trace of spines or tubercles. Taken 

 near Sarasota. 



M. corona perspinosa Pilsbry, attains large size, shoulder spines 

 horizontal, one, two or three rows; well-developed basal series of 

 spines. From Tampa Bay to Lossman's River. 



M. corona subcoronata Heilprin, less height and greater width 

 than M. corona, one series of horizontal shoulder spines, and one 

 basal series. 



M elongena is predatory upon both pelecypods and gasteropods, 

 and as many as eight individuals have been seen together devouring 

 a living horseshoe crab. The animals respond within a short interval 

 of time to a current-borne taint — always approaching in a direct 

 line and against the current, toward the anticipated meal. 



The following account of the attack of M elongena upon the 

 large bay scallops was given by a Sanibel net fisherman — "Out on 

 the flats when we are sitting in the boat waiting for the tide to 

 turn, we can see the crown conchs creepin' up on the scallops on 

 the bottom; the old conch will slide up to about three or four inches 

 from the scallop and then leap on him — they hold the scallop in 

 their foot and stick their trunk through the little nick below the 

 scallop's ear. The scallop flaps his shell to get away but this only 

 gives the conch the chance to get his trunk in deeper". 



Family FASCIOLARIIDAE 



This family, whose members are generally distributed through- 

 out warm seas, counts among its species one of the largest known 

 univalve shells, Fasciolaria papulosa Sowerby. Other species of the 

 group have shells of diminishing size to the one inch altitude of a 

 small Leucozonia. 



The animals are sluggish in movement and somewhat timid, 

 although they are both predatory and carnivorous, pelecypods and 

 gasteropods are indiscriminately attacked by them. They have been 

 seen to prey upon Strombus, M elongena, Mercenaria {"Venus"), 

 and Pecten. 



