Invertebrate zoology /
Hegner, Robert William, 1880-1942.
Invertebrate zoology / Robert W. Hegner, Joseph G. Engemann. - 2nd ed. - New York : Macmillan, 1968. - xviii, 619 p. : ill. ; 24 cm.
Invertebrates.
Invertebrate zoology / Robert W. Hegner, Joseph G. Engemann. - 2nd ed. - New York : Macmillan, 1968. - xviii, 619 p. : ill. ; 24 cm.
Invertebrates.