MANUAL OF CONCHOLOGY. 



t 



Vol. X, Part Second. 



MONOGRAPHS OF THE TURBINIDiE AND 

 TROCHIDiE, 



BY H. A. PILSBRY, 



Conservator of the Conchological Section, Academy of Natural Sciences 



of Philadelphia. 



Family TURBINIDjE. 



Animal with an oval, broad or narrow foot, truncated anteriorly; 

 rostrum rather short, truncate; tentacles long, slender, cylindrical, 

 the eyes on peduncles at their exterior bases. Across the front of the 

 head, between the tentacles extends the more or less developed 

 "veil" ; and from a point below the tentacles, a fleshy ridge, the 

 "epipodial line" extends backward parallel with the margins of the 

 foot, and bearing usually several slender cirrhi on either side. 



Radula rhipidoglossate, usually with the formula go 'b'Vb'oo , but 

 sometimes lacking the median and one outer lateral tooth. The 

 lateral teeth are all of nearly the same form ; so that a transverse 

 row of teeth shows only three distinct forms. Jaws usually present. 



Shell turbinate or trochiform, generally solid, smooth or rugulose; 

 aperture circular, oval or subtetragonal ; peristome simj^le. Oper- 

 culum calcareous, heavy, flat or concave with a thin corneous layer 

 internally, convex and calcareous externally, the nucleus multispiral 

 and either subcentral or at the margin. 



The nervous system is chiastoneurous ; ( i. e. the viceral nervous 

 loop surrounding the intestine is thrown into a figure 8 form — the 

 right cord passing above the left — by that torsion of the viceral mass 

 which brings the outlet of the digestive tract to the right side of the 

 neck.) 



The Turbinidce are mostly litoral in station, and inhabitants of 

 tropical and subtroj^ical seas. They are herbivorous. 

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