(a) 



MORPHOLOGICAL CHARACTERS OF TAXONOMIC IMPORTANCE 



300, 



^ 200 



a: 



CO 



u_ 



o 



UJ 

 CO 



i lOo 



I50 



!2 lOO 



(b) == 



CO 



§ 50 



AGGREGATE 



O O „ °o 



o o 

 o 



0S° °o ° OO ° 



'oieggooo o 8 8°%, ^^ 



808 oo @@LooP^fi°°88°^° 8o| 8^ 

 •DoS*Q°°8t« ° o®oo ® 



o 



° °ooi 



•: •.»:'! 



oOo 

 ^ o o c 



O S. thompsofii 

 • S. qerlachei 



lO 



20 30 40 



BODY LENGTH (mms) 



50 



SOLITARY 



o o 



cfco go o o o"o I 



(P<5 



o o ° 

 ^°9°^ 8 § o § 



,®o^o°o88oOooo 



*: .iM'TrJ:* 



O S. fhompsoni 

 • S. qerlachei 



O 



lO 



20 



30 40 



_J 1_ 



-J L- 



60 



I20 



19 



50 60 70 80 90 lOO IIO 

 BODY LENGTH, cmms) 

 Text-fig. 4. Variation in the number of muscle fibres in S. thompsoni and S. gerlachei; (a) the aggregate form 

 (M. I-VI) and (6) the solitary form (M. IV) plotted against body length. 



Table 4. The percentage frequency of occurrence of muscle fibre counts in the solitary and aggregate forms 

 of Salpa fusiformis, S. thompsoni and S. gerlachei ; based on the data plotted in Text-figs. 3 and 4. 



Fibre no. 



10- 20- 

 20 30 



30- 

 40 



70- 

 80 



40— 50— 60- 

 50 60 70 



Solitary (M. IV) 



S. fusiformis Number of specimens 2 26 24 i — — — — 



% 3-8 49-1 45-4 i-Q — — — — " 



S. gerlachei Number of specimens — — 5 40 23 3 2 — 



6-8 54-8 31-5 4-1 2-7 — 



5. thompsoni Number of specimens • — ■ — — — — — 25 36 47 



% ______ 18-5 26-6 34' 



80- 90- 100- no- 120- 130- 

 90 100 no 120 130 140 



13 10 



9-6 7-4 



I 



07 



3 



2-2 



Fibre no. 



40- so- 

 so 60 



31 



S. fusiformis Number of 1 2 

 specimens 

 % 26-7 69-0 



S. gerlachei Number of — — 



specimens 



0/ 



/o 



S. thompsoni Number of — — 



specimens 



0/ . 



/o 



60- 



70 



4-4 



1 10- 

 120 



120- 130- 140- 150- 160- 170- 180- 190- 200- 210- 220- 230- 

 130 140 ISO 160 170 180 190 200 210 220 230 240 



Aggregate (M. I-VI) 



— 7 



17 



27 



25 



■S 20-7 32-9 30-5 

 — — — II 



7-3 — 

 16 29 



34 31 16 13 S 

 7-0 IO-2 18-5 21-6 19-7 IO-2 8-3 3'2 



I I 



0-6 0-6 

 3-2 



