tou2pt. 2.J A TAXONOMIC STUDY OF THE SALPIDAE METCALF. 63 





Cat. No. 6570, U.S.N.M. (aggregated form), Albatross station D 5175 

 Sulu Sea, Southeast of Cagayanes Islands, Philippine Islands; March 

 8, 1908; surface; surface temperature, 82° F.; 100 + specimens. 



Cat. No. 6590, U.S.N.M. (solitary form), Albatross station D 5616, 

 Molucca Passage, Philippine Islands; November 

 22, 1909; surface; surface temperature, 84° F.; 

 one specimen. 



Cat. No. 6591, U.S.N.M. (chain form), Alba- 

 tross station D 5128 ; Sulu Sea, vicinity southern 

 Panay, Philippine Islands; February 4, 1908; 

 surface; surface temperature, 80° F.; 15 + 

 specimens. 



Cat. No. 6592, U.S.N.M. (aggregated form), 

 Albatross station D 5186, between Panay and 

 Negros, Philippine Islands; March 30, 1908; 

 surface; surface temperature, 80° F.; surface 

 density, 1.02530; 25 + specimens. 



Cat. No. 6611, U.S.N.M. (aggregated form), 

 Albatross station D 5234, between Bohol and 

 Leyte, Philippine Islands; May 7, 1908; sur- 

 face; surface temperature, 84° F.; surface 

 density, 1.02531; 36 specimens. 



Cat. No. 6621, U.S.N.M. (solitary form), Alba- 

 tross station D 5601, Gulf of Tomini, Celebes; 

 November 13, 1909; surface; surface tempera- 

 ture, 83° F.; two specimens. 



Cat. No. 6623, U.S.N.M. (aggregated form), 

 Albatross station D 5437, W. coast of Luzon, 

 Manila Bay to Lingayen Gulf; May 8, 1909; sur- 

 face; surface temperature, 86° F.; one specimen. 



FlO. 35.— RlTTERIA HEXAGONA, 



solitary form, dorsal view. 

 From Traustedt (1885). 



RlTTERIA HEXAGONA, solitary form. 



The very broad body muscles are irregularly continuous across the 

 mid-dorsal line, but are widely interrupted ventrally (fig. 35). Their 

 disposition is not identical on the right and left sides. At the posterior 

 end of the body the body muscles form an almost complete layer, the 

 degree of antero-posterior fusion between tho successive muscle bands 

 differing in different individuals, so one can not say how many such 

 bands are typically present. Among my specimens I find individuals 

 showing 9 on one side and 10 on another; 10 on each side; 10 on one 

 side and 11 on the other; 11 on each side; 11 on one side with 12 on the 

 other; and, in one of tho largest specimens, 12 on each side. 



The intermediate muscle (i. m.) seems to be the very broad band 

 which lies across the dorsal surface, in front of tho ganglion (fig. 36). 

 2621— Bull. 100, vol. 2—19 5 



