protoconchn.

1878 R. Owen in Proc. Zool. Soc. 972 Every chambered and siphonated shell begins in this simple fashion. The protoconch is cup-shaped or flask-shaped, and includes a similar but smaller blind beginning of the siphon.

1888 Proc. Boston Soc. Nat. Hist. 23 542 Professors Hyatt and Brooks consider the protoconch in cephalous molluscs as..probably derived from the periconch of Scaphopods.

1902 Amer. Naturalist 36 918 The apical whorl of a gastropod shell has come to be generally known as the protoconch, though this term had been preoccupied for the corresponding apex of cephalopod shells.

1958 J. E. Morton Molluscs vii. 143 A multispiral protoconch with a small apex and many whorls denotes a long-swimming larva, and is thus characteristic of most gastropods of warm seas.

1995 P. J. Hayward et al. in P. J. Hayward & J. S. Ryland Handbk. Marine Fauna N.W. Europe x. 491/1 The apical whorls represent the larval shell, or protoconch.

1890 Cent. Dict. Protoconchal, pertaining to the protoconch.

1959 Micropaleontology 4 386/1 The two protoconchal spires nearly symmetrical.

1984 Museo Regionale di Scienzi Naturali Bollettino 2 257 All generic assignments are reviewed and discussed on the basis of the protoconchal characters and of some significant shell features.