PHYLUM MOLLUSCA 



265 



extended, seize the victim with their suckers, and draw it back 

 to the arms, which hold it firmly to the mouth. The funnel (j) 

 is a muscular tube extending out be- 

 yond the edge of the mantle collar (2, p) 

 beneath the head (4). Water* is ex- 

 pelled from the o 

 mantle cavity (Fig. 

 192, M.C) through 

 it. The funnel is 

 the principal steer- 

 ing organ; if it is 

 directed forward, 

 the jet of water 

 passed through it 

 propels the animal 

 backward; if di- 

 rected backward, 

 the animal is pro- 

 pelled forward. 



A thick muscular 

 mantle -encloses the 

 visceral mass and 

 mantle cavity. It 

 terminates ven- 



n . 77 FIG. IQI. The squid, 



trally in a collar Loligo pealii> side view 



A, anterior; D, dorsal; 



P, posterior; V, ventral. 



i, fin; 2, edge of mantle; 



j, siphon ; 4, head ; 



5, arm; 6, long arm with 



suckers; 7, arm; 8, eye; 

 by three pairs of 9, edge of mantle. (From 

 . , , , . Williams.) 



interlocking sur- 



(Fig. 191, 2, 9} 

 which articulates 

 with the visceral 

 and funnel 



mass 



FIG. 192. Diagram 

 showing the structure of 

 the squid, Loligo pealii. 

 A 1 , arm; A 4 , long arm 

 with suckers; An, anus; 

 Ca, caecum ; E, eye ; 

 Gi, gill ; Go, gonad ; 

 75, ink-sac; LV, liver; 

 M . C, mantle cavity ; 

 Ne, nephridium; Ph, phar- 

 ynx; Pn, pen; Si, siphon; 

 Si, stomach; SiV, valve 

 of siphon. (From Wil- 

 liams.) 



faces. Water is drawn into the mantle cavity at the edge of 

 the collar by the expansion of the mantle and forced out through 

 the funnel by the contraction of the mantle. On each side of 

 the animal is a triangular fin-like projection of the mantle 



