90 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



accessory masses of cells (eq) lie below the anterior ends of the horse- 

 shoe, instead of below its sides. 



ti-2 



U.3 



Fig. 74.— Salpa fuslformis, solitary form, oral muscles of the right side, seen from the inside. 

 X 12 diameters. (Drawn by Hoyt S. Hopkins.) 



The ducts of the neural glands are larger than in most species. 

 The disks are of the usual type. 



IX 



There is a distinct outgrowth of 

 large cells from the ganglion, on 

 each side, lying close pressed be- 

 tween the ganglion and the disk 

 of the gland. No small-celled 

 outgrowth is distinguishable. 



SALPA FUSIFORMIS, aggregated form. 



This closely resembles the ag- 

 gregated Salpa maxima, except 

 that both the anterior and pos- 

 terior protuberances from the 

 body are generally longer 1 and 

 not so ventral (figs. 77 and 78), 

 while the asymmetry of the pos- 

 terior end is less noticeable. The 

 body musculature is identical in 

 the two species, except that in 

 Salpa fusiformis muscles IV and V always approach each other and 

 often are in contact laterally. There is the closest resemblance also 

 in the oral and atrial musculature. 



Fig. 75.— Salpa fusiformis, solitary form, atrial 

 muscles viewed from the left side. From 

 Streiff (1908). 



Not infrequently these protuberances are short, as shown in figure si. 



