MORPHOLOGY OF THE HELICINID^. 



807 



Li. Liver. 

 li. d. Liver-ducts. 



M. Mantle. 

 M. c. Mantle-cavity. 

 m. g. Hypobranchial gland. 

 n. em. I. Left columellar nerve. 

 n. cm. r. Right columellar nerve. 



n. gen. Genital nerve. 

 n. gl. p. Nerve to pedal gland. 

 n. Ipb. Labio-proboscidean nerves. 



n. oc. Ocular nerve. 

 n. op. I. Left opercular nerve. 

 n. op. r. Right opercular nerve. 

 n. of. Otocyst nerve. 

 n. pal.-c.l. Left pallio-columellar nerve. 

 n. pal.-c.r. Rightpallio-columellar nerve. 

 ti.pal.l. Left pallial nerve. 

 n. pal.r. Right pallial nerve. 

 H.par.l. Left parietal nerve. 

 n. par.r. Right parietal nerve. 

 n. sb.i. Subintestinal nerve. 

 n. ten. Tentacular nerve. 

 od. Oviduct. 

 od^. Descending limb of V-shaped 



portion of oviduct. 

 od'^. Ascending limb of V-shaped 

 portion of oviduct. 

 od. c. a. Anterior odontophoral carti- 

 lage. 

 od. c. p. Posterior odontophoral carti- 

 lage. 

 OS. (Esophagus. 

 ce. p. Esophageal pouch. 

 o. OB. p. Opening of oesophageal pouch 

 into oesophagus. 



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Fig. 17, 



Leftside view of Alcadia palliata. The mantle has been cut through close 



to the left columellar muscle and turned back to expose the interior of the 



mantle-cavitj', the pericardium has also been opened. 

 Dorsal view of the buccal cavity, pharj'nx, and anterior part of the 



oesophagus of Alcadia palliata : the buccal cavity, pharynx, and part of 



the cBsophagus have been laid open ; gl.r., glandular ridge on the floor 



of the oesophagus. 

 A dissection of the oesophagus and pharynx oi Alcadia palliata, seen from 



the left side. 

 A horizontal section through the pharynx and buccal cavity of Alcadia 



hollandi. 



The odontophoral cartilages oi Alcadia palliata, viewed from below. 

 The odontophoral cartilages of JSutrochatella pulcJiella, viewed from above. 

 A dissection of the stomach of Alcadia palliata, viewed from the ventral 



side. 

 A portion of the epithelium of the stomach of Alcadia hollandi, showing 



glandular and ciliated cells. X about 960. 

 Part of a section through the prominent ridge in the stomach of Alcadia 



hollandi, X about 600 ; cu., the thick cuticle covering the ridge. 

 The alimentary tract of Alcadia palliata, showing the arrangement of the 



intestinal coils. 



Alimentary tract of Alcadia hollandi. 

 Alimentary tract of Falmohelicina idee. 

 Alimentary tract of Orobophana ponsonbyi. 

 Alimentary tract of Lucidella aureola. 

 Alimentary tract of JSutrochatella pulchella. 

 A hoi'izontal section through the upper part of the visceral mass of 



Alcadia hollandi. Figs. 17 to 22 are drawn from the same series of 



sections. 

 A section somewhat lower down, showing the origin of the ureter, Ur., 



from the kidney. 



