TRANSACTIONS OF THE ROYAL MICRO- 

 SCOPICAL SOCIETY. 



DESCRIPTION OF PLATES XII & XIII. 



lllustiating Mr. Hogg's paper on the Lingual Membranes of 

 Mollusca, and tlicir Value in Classification, (pp. 93 — 104.) 



PLATE XII. 



Rhipidoglossa (00—3—1—3—00). 



Fig;. 



57. — Pltarmophorus Australia, New Zealand. Odontopliore hold, and an 

 inch and a half or more in lc!Ugth ; colour deep orange. 

 Median broad, rellexed, and produced outwards ; four smaller 

 leeth rcflexed on either side, rieuite'arrned, 1st remarkable for its 

 strength, reflexed, tricuspid ; numerous, smaller gradually dimiaish- 

 ing outwards. The teeth have considerable strength, and appear to 

 belong to an animal feeder. 



5S. — Fissurella reticulata, Mazellan. Median subquadrate, rellexed ; three 

 smaller teeth reflexed on either side. Pleura armed, two strong 

 sickle-shaped teeth, flanked by smaller. Specimen rendered too 

 transparent by the balsam mounting. 



59. — Fissurella magella. Odontophore differs in some respects from 

 former. Median broad, slightly produced outwards ; on either side 

 are t liree reflexed teeth, supported by a bold, strong tooth, tricuspid, 

 the siiaft of which appears to narrow oft' and bend on itself ; flanked 

 by numerous smaller teeth, inner border serrated. 



GO. — Margarita Greenlandica, Greenland. Median reflexed, serrated ; on 

 either side five or six much rcflexed teeth; flanked by a wedged- 

 shaped rudimentary tooth, slightly reflexed, and numerous smaller 

 ones diminishing outwards. 



01. — Chito7t fulvus,W^Q Bay. Odontophore long and narrow. Numerous 

 rows of strong hooked teeth. Median small, reflexed, dentate. 

 1st lateral small, reflexed. 2nd tricusjiid, strong, head clump- 

 shaped, shaft long and narrow. 3rd hooked, tusk-like, flanked 

 by four subquadrate teeth set in a tesselated manner in the base- 

 ment membrane. 



02. — Chiton citiereus, Red Sea. Median narrow, reflexed ; the shaft, which 

 is long, articulates with the next tooth, this again with the next, 

 a large and bold bicuspid tooth. There appears to be a double 

 row of black glistening teeth, hooked, with plain cutting edges, 

 separated by a central band, probably muscular; four teeth, 

 subquadrate and slightly reflexed. 



