434 



THE WATERING-POT SHELL. 



^c- 



plished. The third figure represents another species, the SWORD-BLADE RAZOR-SHELL, 

 with the ends of the siphon-tubes just protruding from the extremity. 



IN the next family, called Gaper Shells, because the valves when closed do not unite 

 completely, but leave a moderately wide aperture at the hinder part, the shell is strong, 

 thick, and opaque ; the foot is comparatively small, and the siphons are united and 

 retractile. 



The GAPER SnELLinhabits sandy and muddy 

 shores, and is especially fond of frequenting 

 the brackish waters of river-mouths, where the 

 streams are sure to bring with them a soft de- 

 posit of mud and sand. The species which is 

 represented in the engraving burrows nearly a 

 foot in depth into the sand, and is able to 

 breathe and gain subsistence by the long si- 

 phons which just protrude above the surface. In 

 looking at this animal, and observing its habits, 

 the entomologist is forcibly reminded of the 

 manner in which the rat-tailed maggot, /. e. the 

 larva of Eristatis tenax, the great bee-like fly, 

 with enormous eyes, is in the habit of hovering 

 for a moment over a flower or leaf, settling for a 

 moment, and then darting off again with light- 

 ning speed. Like the Gaper Shell, this larva 

 spends its life deeply buried in the mud, carry- 

 ing on the business of respiration by means 

 of a long tube which, like the siphon of the 

 mollusc, can be retracted or extended at will. 

 The Gaper Shell is much sought after in 

 many places as an article of food, not only by 

 man, but by birds and beasts, such as the 

 walrus and the blue fox. 



THE nearly cylindrical shell seen lying on 

 the ground in the front of the illustration on 

 the opposite page is the WATERING-POT SHELL, 

 a curious creature found in some of the hotter 

 seas. This species is a good example of a 

 family termed the Gastrochasnidae, in which the 

 valves are thin, gaping, and when adult, often 

 connected with a rather long calcareous tube, 

 as in the present instance. 



The Watering-pot Shell derives its name 

 from the curious perforated disc which closes 

 its lower extremity, and bears no small resem- 

 blance to the rose of a watering-pot. In allu- 

 sion to the same peculiarity, the French writers 

 call the animal by the name of Arrosoir. All 

 the species are burrowers, some into coral, 

 some into stone, some into shells, and others 

 into sand, as is the case with the creature which 



we are now examining. From the other end of the tube the siphons can be protruded 



to some extent, and withdrawn when the animal is alarmed. 



One species belonging to this family, the Gastrochczna modiolina, has been known 



to drive its burrow fairly through some oyster-shells into the ground below, and then 



to make a permanent home by cementing all kinds of materials into a flask-like case 



and fixing its neck into the perforated oyster-shell. 



OAPER SHELL. Mya arearrla. 



