Bui,L. U. S. B. F., 1909. 



Pl,ATE XL VI. 



■ r^-.m 



rm 







v.-^&5i®\^: 



I 





Fig. 



ad.Tn 





Fig. 2. 



Eit 



0.&.<\l 



c/l rp J 



V 











i, //;;/< 



/!./,/ 







Fig. 3- 



Fig. I. — From transverse section of ovary of lobster SJ4 inches long, July 25, showing cluster of epithelial cells on crest of fold, 

 and their differentiation into primordial ova (eO and folUcle cells {fol. ep), with formation of egg-sacs {fol); b. m, basement 

 membrane; Bl. s, blood sinus; ov. eP, epithelium of ovary. Enlarged about 230 times 



Fig. 2. — Part of longitudinal section of first larva, at point of attachment of adductor mandibuU muscle {ad. ra), showing fibillar 

 modification of epithelium {fh. ep), and basement lamella (6m); bl. v, blood vessel; cut, cuticle; 7ns, mesoblast. Enlarged 

 about 230 times. 



I?IG. 3. — Part of transverse section of dactyl of soft lobster, close to spines of dentate margin, showing the enamel (Eit), pigmented 

 and calcified layers of shell {p. and c. I), chitogenous epithelium (ck. ep.), and involuntary muscle spongew*ork (t. mu), with 

 blood lacunae (6/. I), in "fine meat" of claw tip; 6. c, blood corpuscles; s, seta. Enlarged about 115 times. 



