92 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



parable to the mass of similar cells in the ganglion of S. maxima and 

 to the masses of less modified cells in a similar position in Apsteinia 



punctata (figs. 56, p. 77, and 

 57 , p. 78) and Salpacylindrica 

 (figs. 87, p. 98, and 89, p. 99). 

 The pigment cells of the 

 large eye in the aggregated 

 form of Salpa fusiformis lie 

 outside the limiting mem- 

 brane of the eye, and so 

 appoar to bo mesodermal. 

 In all the aggregated Cyclo- 

 salpas, as in all solitary 

 forms, the pigment cells are 

 inside the limiting mem- 



Fig. 79.— Salpa fusiformis, aggregated zoom, sagittal brane 01 tllO eye, Wnicn 



SECTION OF THE EYES AND PART OF THE GANGLION- jg COntinUOUS with that Of 

 X 155 DIAMETERS. FROM METCALF (1903, C). , , , . _,. 



the ganglion. They appear, 

 therefore, to be ectodermal. There have not been sufficiently careful 

 studies of the development of these cells to determine whother the 

 discrepancy is real or only apparent. 



The neural gland is of the usual character. There is a pair of large- 

 celled outgrowths from the ganglion toward the disks of the gland. 



Fig. 80.— Salpa fusiformis, form aspera, solitary indi- 

 vidual in postero-dextro-dorsal view. After Ritter 



(1905), MODUIED. 



SALPA FUSIFORMIS, Form ASPERA (Chamisso, 1819). 



S. aspera Chamisso, 1819. 



(?) S. vaginata Chamisso, 1819. 



S. echinata Herdman, 1888. 



S. fusiformis, var. echinata Apstein, 1894, a. 



S. fusiformis, form aspera Ihle, 1911. 



The form aspera (figs. 80 and 81) is 

 very similar to Salpa fusiformis proper. 

 The musculature and all tho internal 

 structure, including the character of 

 the eyes, are practically idontical in S. fusiformis and its form 

 aspera in both solitary and aggregated individuals. The aggre- 

 gated zooids of both the main species and tho spinose form may 



Fig. 81.— Salpa fusiformis, form 

 aspera, aggregated zooid in 

 dorsal view. x 6 diameters. 

 From Apstein (1906, 6). 



