PHKYGAXEIDiE. 



C19 



it. The body of the larva is curved, though not spirally, antl 

 when out of the case it is cylindrical, thickest on the basal 

 ring of the abdomen, and is pale greenish, while the head, 

 thorax and legs are brownish ; it is .25 of an inch in length. 

 The head is hairy and is smaller than usual, a little narrower 

 than the thorax, with black, acute unidentate mandibles. 

 The thoracic rings are horny above, somewhat hairy, and 

 the legs are slender and hairy. The abtlouieu 

 ends rather abruptl}^, with two short tubeicle.s 

 ending in a hook, both sides being alike, the 

 body throughout as symmetrical as other larvie F)g. w:;. 

 of this family, though living in a helicoid case. On each side 

 of the basal segment of the abdomen is a lunate, corneous, 

 hairj' spot, by whicli the larva probably retains its hold in the 

 case when the head and thorax are protruded. The case is 

 usually very regularly helix-like in form, tliough the umbilicus 

 varies in size. It is composed of tine grains of sand so 

 arranged that the outer a 



surface is smooth. It is 

 closed during the pupa 

 state by a dense, silken 

 concave, suborbicular 

 operculum, with concen- 

 tric lines, rounded on the 

 side, and but slightly con- 

 vex on the other, with a 

 slightly curved slit for the 

 l)assage of water situated 

 on the less convex side, 

 each side of the slit be- 

 ing provided with slender 

 straight teeth which near- 

 ly touch each other, thus 

 forming an i m p e r f e c t 

 grate. The larva does 

 not spin a cocoon. Fig. Fig. 6i4. 



613 represents the case of H. arenifem Lea, from Indiana. 

 Mr. J. A. IMcXiel has brought from Pnlvon, west coast of 

 Nicaragua, similar larvse, belonging to a species very closely 



