APPENDIX TO SUPPLEMENTS, PLATE XXI. 



Fig. 



1. Lateral view of the viscera of Waldheimia Australis, after Hancock (' Phil. Trans.,' vol. 148, 2nd part, 

 pi. lvii, fig. 2, 1858). a, Lateral view of the viscera :— a, dorsal surface of animal ; b, ventral 

 ditto; c, c, anterior wall of perivisceral chamber; d, brachial spiral, the left lateral portion 

 of the arm having been removed ; d' right lateral portion of ditto ; e, great brachial canal ; /, 

 small or efferent ditto ; g, brachial grooved ridge ; h, sheath of transverse portion of calcareous 

 loop ; i, i, dorsal extremities of anterior and posterior occlusors ; j, ventral portion of ditto ; k, 

 divaricators ; k', accessory ditto ; k", extremities of ditto attached to cardinal process ; I, I, por- 

 tions of ventral adjustors ; I', I', portions of dorsal ditto ; m, peduncle ; n, peduncular capsule ; 

 o, peduncular muscle ; p, oesophagus ; q, stomach, with the roots of the biliary ducts exposed, 

 the left lobes of the liver having been removed ; r, right lobes of the liver seen through the 

 dorsal mesentery ; s, intestine ; t, portion of gastro-parietal band ; t\ central ditto ; u, ventral 

 mesentery ; u', upper portion of ditto ; v, right oviduct, the left one is almost entirely removed ; 

 w, heart ; x, dorsal pallial artery ; y, ventral ditto ; y ', blood sinus in mesenteric membrane ; z, 

 oesophageal ganglia. (P. 320.) 



2. Ventral extremity of anterior occlusor of W. Australis, after Hancock, a, lleshy contractile portion ; 



b, b, white tendinous ditto. 



3. Side view of the viscera of Rhynchonetlu psittacea, after Hancock ('Phil. Trans.,' vol. 148, pi. lxi, 



fig. 2). a, anterior wall of perivisceral chamber; b, b, brachial organs; c, ventral terminations 

 of occlusor muscles ; c', c', dorsal terminations of anterior and posterior occlusors ; d, d, 

 divaricators, the left one cut through ; d', ventral wall of perivisceral chamber ; e, peduncle ; 

 e, capsule of ditto ; /, peduncular muscle ; g, oue of the dorsal adjustors ; h, one of the ventral 

 ditto ; i, oesophagus ; j, stomach, exhibiting the two openings of the left hepatic ducts, the liver 

 having been removed from this side ; k, right lobes of the liver ; k', posterior lobe ; k", anterior 

 ditto ; /, dorsal mesenteric membrane ; in, m, ventral ditto ; n, lateral gastro-parietal band ; o, 

 central ditto ; p, p, ilio-parietal bands ; q, heart ; r, branchio-systemic vein ; s, aorta ; t, t ' , 

 dorsal and ventral pallial or genital arteries ; u, right ventral oviduct; v! , portion of left ditto cut 

 through ; v, oesophageal ganglia ; w, sheath of crural process or oral lamina ; x, orifice leading 

 into ditto ; y, portion of ditto of the opposite side ; z, terminal sac of the left great brachial 

 canal ; z ', ditto of the right or opposite arm, seen through the mesenteric membrane. (P. 331.) 



4. View of the pallial chamber of Lingula anatina, the ventral pallial lobe turned back, after Hancock 



('Phil. Trans.,' vol. 148, pi. Ixiv, fig. 3). a, ventral lobe ; b, dorsal ditto; c,c, great pallial 

 sinuses ; d, d, lateral branches of ditto ; e, e, puckers of lateral branches, occasioned by 

 contraction of the pallial margin;/,/, terminal extremities of lateral branches; g, g, central 

 branches of the great sinuses ; h, marginal fold ; i, a few of the setse ; j, extreme pallial margin ; 

 k, brachial apparatus ; I, I, cirri ; m, brachial fold ; n, mouth ; o, o, external orifices of oviducts. 

 (P. 326.) 



5. A few eggs of Terebratulina septentrionalis (after Morse) in their natural position, from pallial 



membrane of an adult individual, 



