1830 ANNIVERSARY MEMOIRS OF THE BOSTON SOCIETY OF NATURAL HISTORY 1880

THE DEVELOPMENT OF THE SQUID.

LOLIGO PEALII (LESUEUR).

Fig. 19

Diagrammatic view of the right side of a Pulmonate embryo, with its dorsal surface above; f, foot; h, neck region; m, mouth; ma, mantle; c, foot-sinus; r, rectum; sa, shell area; ski, shell; t, tentacle; v, velum.
a', a", a"', a"", the four arms of the right side; f the fin; g, the gill; n, the branchial heart; m, the free edge of the mantle; nc, the neck cartilage; si, the siphon tube; si', the lateral chamber of the siphon; v, the valve of the siphon; x, the space between the integument and the surface of the external yolk; y', y'', y"', y"", the four divisions or regions of the yolk.