114 



HANDBOOK OF LNVEKTEBKATE ZOOLOGY. 



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w. 



Fro. 65. D- 



FIG. 65. Dorsal view of a larva a little older, slightly flattened by 

 pressure. (Drawn from nature by W. K. Brooks. ) 



a. Anterior end. b. Posterior end. c, c. Post-oral arms, a' a'. Pre- 

 oral arms. d. Spicules of side of body. e. Ventral transverse spicule, 

 seen through body. /. Spicule of pre-oral arm. y. Spicule of post-oral 

 arm. i. Intestine, pushed to one side by pressure, k. Point where 

 lateral arm is to be developed. I. Rudiment of a dorsal transverse 

 spicule. m. Mouth, in, e. Mesoderm. ce. (Esophagus, p. Spicular 

 skeleton at posterior end of body. s. Stomach, w. Water tubes. 



