TUNIC AT A. 23 



while the ventral haiul is alisont. In A the ventral liand is f(|ual in extent to the 

 notuchoiil, anil the doisal extends a little beyonil on each side. In B l)otli ventral and 

 dorsal bands arc about twiee the diameter of the uotoehord. Finally, iu C each muscle 

 band is about tliree times the diameter of the uotoehord, and iu some sections I have 

 found a slightly greater development of the muscles. In view of these variations, and 

 of the fact that the subchordal cells are in some cases in one row, iu some in two, or 

 even three in a transverse row, I find it ditlicult to distinguish between Dr. Lohniann's 

 two Autantic species 0. gausslca and 0. vatdivise. The first-named is described* as 

 having " schmaler, die Chorda seitlich kaum iiberragender ^luskulatur," while the 

 second has " Muskulatur breit, etwa 4-mal so breit wie die Chorda " ; but practically 

 both these conditions are found in one tail of our specimens, ami are shown in fig. IG. 



The histological details of the wall of the nntoclimd, the muscular and cpitliclial 

 layers and the test, with part of a subdiordal cell underlying it, are shown in tig. 17. 



( >iK<tri,Ki i:a sp. 



There are also about 20 small tubes containing much smaller specimens of 

 Oikoplcura, which I do not care to refer to a species. Most of them arc probably 

 young, all are very opaque, and some arc shrivelled or nmtilated. The only value 

 of this record is to .show that small forms of Oikopbura do occur, in some cases in 

 considerable numbers, at the localities given in the following list : — 



1. " 31. xii. 01 ; Lat. (U" 12' 39" S. ; Long. 173'^ 2i)' 42" E." {One specimen.) 



2. "Winter Quarters, G. v. 03 ; No. 4 Hole, 5 fms." (Two .specimens.) 



3. "Winter Quarters, 15. v. 03 ; No. 8 Hole, 10 fms." (One .specimen.) 



4. " 18. v. 03; No. 4 Hole." (Three specimens.) 



5. "Winter Quarters, 29. v. 03 ; No. 4 Hole, 5 fms." (Eighty specimens.) 

 G. "Winter Quarters, 1. vi. 03 ; No. 8 Hole, 10 fms." (Five specimens.) 



7. "Winter Quarters, 1. vi. 03 ; No. 8 Hole, 10 fm.s." (One specimen.) 



8. "Winter Quarters, 28. vi. 03; No. 8 Hole, 10 fms." (Twenty-one 



specimens.) 



9. " Winter Quarters, 13. vii. 03 ; 10 fms." (Three specimens.) 



10. " 24. vii. 03 ; No. 8 Hole, 10 fm.s." (Six specimen.s.) 



11. "Winter Quarters, 1. viii. 03; No. 8 Hole, 10 fm.s." (Seven specimen.s.) 



12. "Winter Quarters, 13. viii. 03; No. 8 Hole, 10 fm.s." (Three .specimens.) 

 l.'i. '■ Winter Quarters, 21. viii. 03 ; No. 8 Hole, 10 fms." (Seventeen .specimens.) 



14. ' Winter Quarters, 2. xi. 03; No. 12 Hole, 10 fm.s.' (Three specimens.) 



15. "12. vi. 04; Surface, Lat. 49° 40' S. ; Long. 172° 18' 30" W.' (140 



•specimens.) 

 IC. ••21. vi. 04; Lat. 5G 12' 45" S. ; Long. 130" LH' 30" W., 10 fms." (Fifty 

 .specimens.) 



• Luhiiiaiin, op. cit., p. ItJ'J. 



