THE NATURAL HISTORY SURVEY. 381 



Proc. Cal. Acad. Sci. Proceedings of the California Academy of Sci- 

 ences. 



Proc. Daven. Acad. Sci. Proceedings of the Davenport Academy of 

 Sciences. 



Proc. Iowa Acad. Sci. Proceedings of the Iowa Academy of Sciences. 



Proc. Phil. Acad. Proceedings of the Academy of Natural Sciences 

 of Philadelphia. 



Proc. U. S. Nat. Mus. Proceedings of the United States National 

 Museum. 



Proc. Zool. Soc. or P. Z. S. Proceedings of the Zoological Society of 

 London. 



Quar. Journ. Conch. Quarterly Journal of Conchology. 



Trans. Acad. Sci. St. Louis. Transactions of the Academy of Sciences 

 of St. Louis. 



Trans. Amer. Phil. Soc. Transactions of the American Philosophical 

 Society, Philadelphia. 



Trans. 111. State Ag. Soc. Transactions of the Illinois State Agricult- 

 ural Society. 



Trans. Wagn. Inst. Sci. Transactions of the Wagner Free Institute 

 of Science, Philadelphia. 



Ver. Moll. Vermont Mollusca. 



XIII. GLOSSARY. 



In the following pages the technical and other terms used in the body 

 of this work are defined. References are also made to illustrations where 

 they will in any way add to the understanding of a word. Terms which 

 are adequately explained in the text are not here included: 



Abdominal sac. That portion of the Unionidae which contains the 

 stomach and to which the gills are sometimes suspended. 



Acephalous. Headless. 



Acinose. Full of small bulgings; resembling the kernel in a nut. 



Aculeate. Very sharply pointed, as the teeth on the radula of some 

 snails. 



Acute. Sharp or pointed, as the spire of a shell (pi. xxxv, fig. 1), or 

 the lip of a shell (pi. xxviii, fig. 15). 



Acuminate. Long and tapering, as the spire of some shells (pi. xxxii, 

 fig. 3). 



Admedian. Next to the central object, as the lateral teeth on the lin- 

 gual membrane. 



Afferent. To bring in; when relating to a vessel or duct, indicating 

 that it brings in its contents. 



Alate. Wing-like, as the dorsal part of some Unios (pi. xviii). 



AmoL-boid. Shaped like an Amoeba, a small animalcule. 



Amorphous. Without distinct form. 



Amphibious. Inhabiting both land and water. 



Amphidetic. With the ligament on both sides of the umbones. 



Analogue. A likeness between two objects when otherwise they are 

 totally different, as the wing of a bird and the wing of a butterfly. 



Anastomosing. Coming together. 



