1:1 ! i in N. i PO PI \ i 



KK8. I'A'.K. 



A'. The origin, oil tin- left side, of tin 1 lllllx'lc which pro 



t rudes !!; . The inner concave mifiMM "f 



slK'll inn- . The I ermi n;it i< >n of the ii'_Jit nn; 



which tlic \en 'iimimicates with tin- ah 



, dominal cavit I'iic e\e hiiil open. [,. The pedicle. 



7. The pupil seel) from \\ itliin. /'. The cut -edge o!' t lie selei ot ie. 

 ft. The ret inn. t. The dark pigment deposited on its anterior 

 surface, and lining t he e;i\ ity of t lie globe. 1. Tlie brain, or 

 central eonnnissni e. '.*. Anterior BUIMBBOphag6ft] ganglions. 

 :'.. < >phthalmir ganglions, t. Posterior tUD-CBSOphageaJ 

 -lion-. r>. N.-rves of tlie digital tentacles. 6. Nerve- ! the 

 external labial tentacles. 7. 'I'he nerves brin^ii)- tlm labial 

 gangUonsintOOOmmnnicatiOIl with Ihe anterior siil.-.e-opha^eal 

 lion-. 8, [nteinal labial gangliOIUL '. Nerves of the in- 

 ternal labial tentacles. 10. Olfactory nerves. 11. Infnndibnlar 

 nerve-. It?. Tin- origins of the lingual and maxillary nerves. 

 i:!. Nerves of the groat shell-muscles. 14. Visceral nerve*. 

 !.". P.ranehial nerves. 16. Visceral ganglions. 17. Nerves 

 ramifying on the vena cava. 



'.'. The olfactory lamina- magnified and separated :'.." 



::. Brain of Cuttle-fish (Sepia officinalis, L.) 



1. The brain, corresponding to the central commissure of the 

 Nautilus. 2. The anterior suli-u-sophageal mass, or Pes anser- 

 inus, giving oil' (5) the nerves to the arms. 3. The great reni- 

 form or ophthalmic ganglions. 4. The i>ostorior snb-cvsophageal 

 mass, giving oft' (6) the nerves to the cloak ; and (8) the 

 nerves to the viscera. 7. The ganglion stellatum. 9. Two 

 small spherical bodies attached to the pedicles of the ophthal- 

 mic ganglions. 



Plate 3. 



1. Anatomy of Nautilus Pompilius. From Owen, Memoir on 



Pearly Nautilus, pi. 2 25 



a. The mantle, b. Its dorsal fold collapsed, c. Its anterior 

 margin, d. The process of the mantle which separates the 

 funnel from the head. e. Convexities produced by the ovarian 

 gland. /. Orifice of the funnel a little widened; the funnel 

 itself is 'drawn down to show the surface of the oval sheath on 

 which it rests, g. The levatores infundibnli exposed by laying 

 open the canals in which they were concealed, h. The hood. 

 i. Its superior plane surface longitudinally divided. /.-. The 

 cut surfaces. /. The smooth internal surface of the oval 

 Sheath, m. The (limitations, showing their orifices, the tent a- 

 'i-ing retracted (the entire number is given on the right 

 side . ///'. Tlie large papillose digitation. //. The inferior 

 parietes of tlie oral sheath, o. The external labial pIO06C 

 //. The internal labial proee>M->. </. The convex outer surface 

 Of the or-an of smell. /. The labial tentacles, x. One of the 

 Ophthalmic tentacles, /. The eye. ?/. The inferior ridge. 



2. A nojtht halm ic tentacle magnified, showing its laminated .structure. 

 :',. A digitation with its tentacle magnified. 



a. The free extremity of the digitation. a'. The nit-sur- 

 face i from the pariete> of the head ; '. The digital 

 tentacle, b'. Tin- eut->urface f the tentacle, exposing ,-. The 

 central nerve. 



