MOLLUSCS, VERMES AND HYDROZOA 



FIG. 158. Goniohasis njirginica. 



near the middle of the body 

 whorl, but one or both are 

 sometimes absent. The slen- 

 der body is pale orange above 

 and bluish white below, 

 banded by irregular interrupt- 

 ed black lines. It occurs in 

 the above mentioned local- 

 ities and is very abundant in the 

 Delaware and Schuylkill rivers. 



G. multineata. Fig. 159, is also common in the tributaries of the 

 Delaware river and in the Middle States. It has a gradually tapering very 



slightly convex ^ to ^ inch 

 long conical yellowish-brown 

 shell of seven whorls marked 

 by a number of reddish or 

 brown bands, a pointed ob- 

 long aperture and a usually 

 eroded apex. It is also com- 

 mon to Eastern and Middle 



FIG. 159. Goniobash multineata. 



States river systems. 



Anculosa. Many species occur in all the Middle-Western and South- 

 ern States but only one species is generally distributed in the Middle States. 



A. carinata,Fig. 160, has a conical dark horn-colored or blackish ^ inch 

 long shell, very variable in appearance, with three or four whorls, all more 

 or less keeled on the 

 middle of the whorls. 

 The suture is but slightly 

 indented, the apex often 

 truncated but usually 

 eroded, and the aperture 



oval and one-third as fig. 160. Ancuhsa cannatus. 



longas the shell. Varieties of this species are very generally found in streams 

 and rivulets throughout the Middle and some of the New England States. 

 SircciNEA. This genus contains the most generally distributed semi- 

 aquatic snails which are only a part of their existence in freshwater, making 

 their homes in marshes and the mudbanks of ditches, ponds and streams and 

 are found in swampy places or on plants along the banks. They are to be 

 distinguished from the aquatic snails by the presence of four cylindrical 

 tentacles, the longer bearing the eyes. They are not desirable in the 

 aquarium, but are frequently introduced with aquatic plants. 



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