vou2,pt. 2.] A TAXONOMIC STUDY OF THE SALPIDAE METCALF. 85 



The atrial muscles are sufficiently shown in figures 64 and 66 with- 

 out description. 



SALPA MAXIMA, aggregated form. 



The shape of the body and the 

 character of the musculature is 

 shown in figures 67 and 68. 

 There are six body muscles, 

 I and II being fused dorsally, 

 also III and IV. Muscles V 

 and VI approach dorsally and 

 often touch, but do not unite. 

 Muscles II and III touch but 

 are not fused, though often 

 they interlock as shown in fig- 

 ure 67. Muscle VI shows the Fig. 66— Salpa maxima, solitary form, atrial 



usual anterior and posterior musculature seen from the left side, from 



1 Streiff (1908). 



branches. 



Both lips are incurled to act as valves, the lower lip more so than 

 the upper. Streiff 's figure of an inside view of the lips (fig. 69) 



a.o. 



Fig. 07.— Salpa maxima, aggregated zooid. dorsal view, x 2 diameters. (Drawn bt Hott S 



Hopkins.) 



W.a. 



Fig. 68.— Salpa maxima, aggregated zooid, seen from the right side, x 2 diameters. (Drawn 



by Hoyt S. Hopkins.) 



shows well the way in which the muscles aid the lips in their valvular 

 action. The cloacal musculature (fig. 70) is of the same general 



