PLATE V. 



Fig. II 8. PnciunonodcrDia licterocotyluin n. sp. Ventral view. 6 X. 



Fig. \\%A. Lateral gill of the same. 



Fig. iiSB. Posterior gill of the same, dorsai view. 



Fig. 119. Acetabuliferous appendage of the same; out-stietched, from the inside. 



Fig. 120. Pncuiiionodenna pygiiiacuui n. sp. Ventral view. 10 X. 



Fig. 121. Posterior gill of the same, aboral view. d, dorsai; z', ventral. 



Fig. 122. Acetabuliferous appendage of the same; out-stretched, from the inside. 



Fig. 123. Some larval Pnciiuionodcnna, ventral view. 10 • . Strongly contracted. 



Fig. 124. Central nervous system oi Pncuuionodentia nieditcrrancuin (van Ben.). Dorsai view. — Pedal nerves 



and cerebro-buccal connectives not figured. 

 c, cerebral ganglion; a, cerebro-pedal connective; b, cerebro-pleural connective; p, pedal ganglion; 



pi, pleural ganglion; plv, pleuro-visceral connective; v, visceral ganglion. 

 I, optie nerve; 2, olfactory nerve; 3, auditory nerve, turned to the front; 4, nerve to the labial 



tentacle; 5 — 7, nerves to the proboscis, the lips and the buccal appendages; 13, 14, pleural 



nerves to the cervical region ; 15 — 17, nerves to the envelop of the visceral mass; iS — 19, 



nerves to the viscera. 

 Fig. 125. Pedal ganglia of the same. Dorsai view. 



ap, anterior pedal commissure; /, pedal ganglion; a, cerebro-pedal connective, ot, otocyst. 



8, nerve to the foot; 11 — 12, anastomosing nerves to the fins; 9 — 10, anastomosing nerves, the 



function of which remained unkiiown to me. 

 Fig. 126. Clioiiopsis niicroceplialiis n. sp. Ventral view. 4 X. 

 Fig. 127. The same, from the left. 4 X. 

 Fig. 128. Radula of the same. 



Fig. 129. Notobranchaea inopinata Pels. Ventral view. 10 X. 

 Fig. 130. The same specimen. Dorsai view. 10 ■. 

 Fig. 131. Head of the same, dorsai view. bc, buccal cones. 



Fig. 132. Oral aspect of the head ; cephalic hood nearly closed. //, labial tentacle. 

 Fig. 133. Foot of the same; /, tubercle. 

 Fig. 134. Dorsai crest of the gill of the same. 

 Fig. 135. Radula of the same. 



