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



59 



RITTERIA AMBOINENSIS, aggregated form. 



The aggregated form of this species is known from the studies of 

 Apstein (1904) and Ihle (1910). Ihle's figures and description are 

 much the fuller and will be used here. The shape of the zooids in 

 side view (fig. 31) is very like that of the aggregated Cyclosalpa 



a.o. 



,,slm- 



m.- 



Sjft 



I J? 



flg. 31.— ritteria amboinensis, aggregated zooid, viewed from the left side. x 11 diameters 



From Ihle (1910). 



baleen (pi. 8). In dorsal view (fig. 33, B) or ventral view (figs. 32 

 and 33, A) it resembles Salpa maxima (fig. 67, p. 85). The aggre- 

 gated Apsteinia magalhanica (fig. 63, p. 82) and Ritteria hexagona 

 fig. 41, p. 67) have somewhat the same shape in dorsal view. 



J> W,a 



<stm. 



1 JT M J?- jr 



Fig. 32.— Ritteria amboinensis, aggregated form, ventral view. X 11 diameters. From Ihle 



(1910). 



The body muscles are asymmetrical. There is a short, wide inter- 

 mediate muscle, incomplete both ventrally and dorsally (fig. 31). 

 It must function more in connection with the oral system than with 

 the body muscles. Six body muscles are present, I and II united 



