ZOOLOGY. 357 



terior portion of the dorsal fin is supported by numerous articulatad 

 branching rays, which are sheathed at the base by two or three rows 

 of scales, separated from those of the body by a rather broad and deep 

 scaleless furrow. This last peculiarity has not yet been observed in any 

 other fish. The alimentary canal is remarkably uniform in width for 

 its whole length. There are no coecal appendages in any part of the 

 intestine. The ovary consists of a large bag, of a light violet color, 

 clear and transparent, subdivided internally into a number of distinct 

 pouches, opening by wide slits into the lower part of the sac. In each 

 of these pouches, a young fish is wrapped up as in a sheet. All the 

 young are packed closely together, to economize space ; some having 

 their heads turned forward, and others backward. The number of 

 young contained in the sac seems to vary. Mr. Jackson counted nine- 

 teen ; Prof. Agassiz has discovered only eight or nine in the specimens 

 he has received. 



Of the specimens received here, there are evidently two species, 

 differing from each other by slight physiological peculiarities. The 

 names of Embiatoca Jacksoni and Embiatoca Caryi, have been given 

 them. 





