200 



Southern Cross. 



ir wv. tuke Jiccount <•!' all l(»calities iVuin 40" south latitude soutli- 

 wartls to tlie Antarctic Continent, we find that the following' pelagic 

 Tunicates have been obtained in the area : — 



I'yronoma </ig<iiiteu7n. 



Dolioluia ehrenhergi. 



Salpa costata-tilesii. 



S. echinata. 



S. cordiformis-zonaria. 



S. cylindrira. 



S. runcinata-fusi/or/ais. 



S. 'lemocraiica-mucronatu. 



•S. afrirana-uiaximtt. 



Appen dicularia. 



( )nly two of these species have been found in the corresponding 

 latitudes round the Xorth Pole. 



EXPLAXATIOX OF PLATES. 



Plate XIX. 



Fig. 1. — Part of the branchial sac of Boltenia pachydnriualina showing 

 variationp. 



Fig. 2. — Another part of tlie same branchial sac. 



Fig. 3. — Styda ladea, Hidn., from side, uat. size. 



Fig. 4. — Section of iX)sterior end of same to show thickened pad of mantle 

 and test. 



Fig. 5. — Alimentary canal of !<tyeJa ladea. 



Fig. 6. — Some of the endocarps x 2. 



Fig. 7. — Part of the eudostyle. 



Plate XX. 



Fig. 1. — Tylobranchion aiitarcticum, nat. size. 



Figs. 2 and 3. — Ascidicizooids enlarged. 



Fig. 4. — Dorsal tubercle. 



Fig. 5. — Branchial sac. 



Fig. 6. — A papilla. 



Figs. 7, 8, and 9. — Colonies of DistapHa ignota, Hrdn. 



Plate XXI. 

 Figs. 1-10. — Shajtes of colonies of Atopogaster elongata, Hrdn. 



Plate XXII. 



Figs. 1 and 2. — Colonies of Polydinum adareanum. 



Fig. 3. — Systems of ascidiozooids. 



Fig. 4. — Arrangement nf pigment. 



Fig. 5. — Common cioacal aperture from inside. 



Fig. G. — Lower end of a colony. 



Figs. 7, 8, and fl. — Branchial sacs. 



Plate XXIII. 



Figs. 1 and 2. — Colonies of Psnmmaplidium nigrum. 



Fig. 3. — Branchial sac rif same. 



^""i'n- ■i- — Colony nf FsatnmapHdium antarcticum. 



Fig. 5. — Section of edge of colony. 



Fig. 6. — Part of brancliial sac. 



