PLATE IV. 



Fig. 4. — Mantle chamber of female viewed froui the ventral side. The mantle has lieen turned back over the 

 posterior end of the body. 



B, raised and overlapping border of the nidaniental irland. 



BV, branchial vein of the anterior gill. 



F, liase of funnel. 



GA, anterior gill. 



GP, posterior gill. 



LM, lateral portion of mantle. 



N, nidamental glaml. 



OV, protruding end of oviduct: iividucal i>apilla. 



PA, preanal papilbv. 



SM, shell muscle. 



VM, ventral portion of mantle. 



Y, thickened portion of mantle between tlio inturned ends of the nidamental gland. 

 Fig. ri, — Cephalic region of female viewed from the dorsal side. The hood has been slit open along the median line 

 to show the arrangement of the labial loliesand tentacles. 



B, buccal ma.ss. 



CR, crescentic ridge U]ion tlie jiostcriipr faci' id the hmid. 



DM, dorsal portion of the mantle. 



Ho, hood. 



Ij, lamellated organ upoji the center of the inferior labial lobe. The fan-like cirrus-bearing jiortions of the lobe 



are seen at the sides of the lamellated organ. 

 SLL, superior labial lobe. 

 Fk;. (i. — Funnel, opened and viewed from the ventral side. 



C, infundibular portions of the cartilage showing through the integument ni the ilorsal wall of the funnel. 

 OR, crus of funnel. 



L, ligamentous band nf the integument extemling from the posterior eilge nf the funnel backward nver the 



surface of the shell muscle. 

 M, shell muscle, 

 V, valve ni funnel 



204 



