192 HANDBOOK OF INVERTEBRATE ZOOLOGY. 



FIG. 100. A female specimen of Callinectes hastatus, with the cara- 

 pace removed, showing the viscera in place on the right side, but partially 

 dissected on the left side. ( Drawn from nature by \V. K. Brooks.) 



a. Anterior gastric muscles. 6. Pterocardiac ossicle, c. Middle gas- 

 tric muscles, d. Ophthalmic artery, e. Stomach. /. Pyloric ossicle. 

 ft. Posterior gastric muscles, h. Ovary, i. Liver, k. Branchial cham- 

 ber. I, .Gills. m. Flabellum. n. Flancs. p. Heart, q. Intestinal 

 coecum. s. External mandibular muscles. 



the stomach. They are on the inside of the stomach, but 

 their opacity renders them conspicuous in a surface view. 



d. A "pyloric" ossicle (Fig. 100, f) lies in the dorsal 

 wall of the stomach, near its posterior end. 



e. Notice the anterior gastric muscles (Fig. 100, a) 

 which run from the inner ends of the "cardiac" ossicles to 

 the anterior edge of the carapace. 



f. The middle gastric muscles (Fig. 100, c), running 

 from the " cardiac " to the " pyloric " ossicle. 



g. The posterior gastric muscles (Fig. 100, g) which run 

 outwards and upwards from the " pyloric " ossicles to the 

 gastric region of the carapace. 



h. A little posterior to the ends of these muscles notice 

 the enlarged ends of the internal mandibular muscles, 

 which are also attached to the gastric region of the 

 carapace. 



i. On the middle line of the body above the stomach 

 notice^the median, or ophthalmic urlcrij (Fig. 100, d). 



j. Follow this backwards to about the middle of the body, 

 where it enters the pericardium, a slightly transparent 

 membraneous pouch, which lies upon the middle line, 

 under the cardiac region of the crrapace. If the animal 

 be not quite dead the slow pulsations of the heart may be 

 seen through the pericardium. 



k. Posterior to the pericardium, on the middle line of 

 the body, there is a hollow, somewhat below the level 



