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HANDBOOK OF INVERTEBRATE ZOOLOGY. 



3. In the centre of this body the single, non-glandular, 

 transparent, thin-walled anterior vena cava (Fig. 179, 10), 

 arises, and runs forward on the median line, through the 



siphon to the head. 



FIG. 179. Deeper dis- 

 section of the circulatory 

 organs of a male speci- 

 men of Loligo Pealii. 

 (Drawn from nature by 

 W. K. Brooks. ) The pos- 

 terior venae cavse (7, q) 

 have been cut. and the 

 right anterior vena cava 

 has been turned to one 

 side to show the systemic 

 heart. The renal organs 

 have been removed, and 

 the intestine (//) and the 

 ink bag (d) turned to the 

 right, to expose the ante- 

 rior vena cava, theliver(S), 

 and the spleen (12). 



The reference letters are 

 the same as in Fig. 178. 



I. Head. 2'. Siphon. 

 S. Valve in orifice of si- 

 phon. 4- Si phonal carti- 

 lage. 5. Lateral chamber 

 of siphon. 6. Median 

 chamber of siphon. 7. Re- 

 tractor muscle of head. 

 8. Retractor muscle of 

 siphon. '9. Liver. 10. An- 

 terior median vena cava. 



II. Hepatic ducts. 

 12. Spleen. 13. Anterior 

 aorta. 14. Posterior 

 aorta. 



Fio. 179. 



4. Near the siphon it gives rise to a branch which pa 

 towards the dorsal surface, and penetrates the soft white 

 //''-/ (Fig. 179, 9), which lies between the large retractor 

 muscles (Fig. 179, 7, 8,) of the head and siphon. 



