SEA-FISHERIES LABORATORY. 495 



Fig. 48. The fore-gut from behind, showing the intrinsic 

 and extrinsic muscles. The postero-lateral 

 dilator has been cut near its insertion at the 

 right side in order to show the antero-lateral 

 dilator muscle. The right posterior dilator of 

 the oesophagus has also been cut in order to 

 expose the lateral dilators of oesophagus, x 3. 



Fisr. 49. Dorsal view of the heart. x 2. 



Fisr. 50. Yiew of the heart from the left side, x 2. 



Plate YIIL 



Fig. 51. General view of the blood system from above. 

 The dorsal region of the carapace has been 

 removed. On the right side the organs remain 

 intact, but on the left side the ovary and 

 digestive gland have been removed. One gill 

 on the left side has also been turned outward 

 in order to show the afferent branchial vein 

 and the branchio-cardiac vein. In this region, 

 also, the flabella of the second and third 

 maxillipedes are seen lying beneath the gills. 

 The course of the bladder is shown on the left 

 side. x 1. 



Plate IX. 



Fig. 52. Yiew of ventral region of post-oral cephalo- 

 thorax to show the sternal artery and its 

 branches. All the muscles have been removed. 

 On the right side the arteries going to the legs 

 are cut short. The inferior abdominal artery 

 is also cut short. x \. 



Fig. 5-°). Dissection of abdomen from the dorsal side to 

 show the superior abdominal artery. The 

 tergal region of the abdomen has been 

 removed. x 1. 



Fig. 54. Dissection of the posterior region of the thorax 

 to show the pericardium, heart, branchio- 

 cardiac veins and efferent branchial veins. 

 Only seven of the gills are shown on the left 

 side, and on the right side only the roots of the 



