AORTIC LIGAMENT IN INDIAN FISHES. 



65 



resting on — or, more correctly, supported by — regularlj^ arranged 

 white round masses of connective tissue (text-fig. 1, lig,). At 

 first sight these round masses look like adipose tissue, but on 

 closer inspection they are found to b^ aggregations of adventitia 

 tissue Avhich form the outermost layer of the wall of the aorta. 



Text- figure 3. 

 ■ d.w. 



d.w. 



Text-figure 4. 



Text-fig. 3. — Pseudentropius garua (X 15). Transverse section of the aorta through 

 the sub-Aertebral region (A-li) of text-fig, 1. 



d.w., dorsal wall of aorta; con., sub-vertebral mass of connective tissue; lig., aortic 

 ligament ; cav., cavity of aorta ; int., intima. 



Text-fig. 4. — Pseude^itropius garua (X 15). Transverse section of the aorta through 

 the sub-iutervertebral region (C-D) of text-fig. 1. 



d.w., dorsal wall of the aorta ; con.', sub-intervertebral mass of connective tissue ; 

 11., neck or the thin suspensory fold of the ligament ; lig., ligament. 



Each of these round masses of connective tissue occurs beneath 

 the body of each vertebra and fits into a depression in the 

 centrum on its ventral side. In certain fishes, as in Laheo rohita 

 and Gatla btichanani, these depressions in the centrum acquire 

 the form of deep notches; and in such cases the masses of con- 

 nective tissue have to be carefully scooped out from the cavities 



Pkoc. Zool. Soc— 1920, No. Y. 5 



