24 W. A. HERDMAN. 



17. "24. vi. 04; Lat. 58 49' 45" S. ; Long. 124 48' W. ( 5 fms." (Twenty- 



three specimens.) 



18. " 25. vi. 04 ; Lat, 59 19' S. ; Long. 120 24' 30" W., 5 fms." (Thirty-eight 



specimens.) 



19. " 28. vi. 04 ; Lat. 59 34' 30" S. ; Long. 106 28' 15" W., 5 fms." (Forty 



specimens.) 



DESCRIPTION OF THE PLATES. 



PLATE I. 



FIG. 1. Styela spectalrilis, from the left side ; natural size. 



FIG. 2. Branchial aperture, from ventral surface ; slightly enlarged. 



Fio. 3. Atrial aperture, from dorsal surface ; slightly enlarged. 



FIG. 4. Musculature of the mantle ; natural size. 



FIG. 5. Part of the branchial sac, showing two folds (br.f.) and the intervening area ; natural size. 



FIG. C. Small part of the branchial sac, between two of the internal longitudinal bars (i.l.l.~) x 50. 



FIG. 7. Tentacles, dorsal tubercle and dorsal lamina ; slightly enlarged. 



FIG. 8. The alimentary canal and the gonads of the right side ; natural size. 



FIG. 9. Some of the larger endocarps ; natural size. 



PLATE II. 



FIG. 1. Halocynthia selosci, Sluiter ; natural size. 



FIG. 2. Section through the test and its dense covering of long spines ; natural size. 

 FIGS. 2x, 2B and 2o. Terminal parts of three test spines of rather different types ; x 50. 

 p jo _ 3_ The body after removal of the test, to show the powerful musculature ; natural size. 

 Fio. 4. Tentacles, dorsal tubercle, dorsal languets, branchial folds, etc. ; natural size. 

 FIG. 5. Part of the branchial sac, showing three folds ; natural size. 



FIG. G. Small part of the branchial sac between two bars, showing the transverse vessels and the 

 stigmata ; X 50. 



