514 MEMOIRS OF THi: NATIONAL ACADEMY OF SCIENCES. 



Plate XXVI. 



Fig. 9. Sectiou tbiougb segiueutiug egg of Alpheus .saulcyi. Eigbt cells present. Yolk uuseg- 

 mented. Egg membraues diagramatically represented, x 70. 



Fig. 10. Surface view of tbe same. Sixteen cells present. Yolk pyramids formed. Tbe peripb- 

 eral nuclei are seen tbrough a thin layer of yolk, x 70. 



Fig. 11. Transverse section tbrougb the immature ovaries of Alpheus. Ovary taken in June, 

 from female "in berry." Diameter of largest ovarian egg, one one hundred and 

 sixty-eighth of an inch. Diameter of extruded egg, one liftieth of an inch. Contents 

 of ovarian egg, oue thirty-seventh of that of tbe extruded egg. x-Sl. 



Fig. VI. Section through segmenting %gg of Alpheus minor, from Beaufort, North Carolina, show- 

 ing nests of nuclei. x70. 



Fig. 13. Swarm or nest of nuclei, like those of preceding figure. x2Sl. 



Fig. 14. Sectiou through egg of Alpheus minor, cutting segmentation nucleus. Nucleus elongated, 

 with irregular, indefinite boundary, x 70. 



REFERENCE LETTERS. 



Al. C, aliiuentary canal. 



B. C, blooil cell. 



B. S., blood space (possibly unnaturally distended). 



Ch., chitinotis egg envelopes. 



D. A., dorsal aorta. 



«, e', yonug ova. 



F. E., ovarian stroma. 



F. E.\ follicular epitheliuni. 



F. C, follicular epithelium. 

 Ger., germogeu. 



Gfer.', position of germogeu iu ovary, with ova nearly ripe. 



G. F., germinal vesicle. 

 0. W., ovariau wall. 



SS, swarm of nuclear bodies. 



Vac, yolk vacuole. 



Vit., vitellogen. 



X, cell shown in Fig. 30. 



Y. P., yolk pyramid. 



