200 PROCEEDINGS OP THE AMERICAN ACADEMY. 



Hist. Nat. Marseille, Zool., Tom. I., Mem. No. 7, 55 pp., 8 PI. 

 1883. 

 Lang, A. 



'84. Die Polycladen (Seeplanarien) des Golfes von Neapel und der 

 angrenzenden Meeresabschnitte. Eine Monographie. Fauna u. 

 Flora d. Golfes v. Neapel, XL, ix -|- 688 pp., 54 Holzschn., Atlas 

 39 Taf. Leipzig, 1884. 



Lillie, F. R. 



'93. Preliminary Account of the Embryology of Unio complanata. 

 Jour. Morph., Vol. VIIL pp. 569-578, PI. XXVIII. 

 Metcalf, M. M. 



'93. Contributions to the Embryology of Chiton. Studies Biol. Lab. 

 Johns Hopkins Univ., Vol. V. No. 4, pp. 249-267, PI. XV., XVI. 

 Rabl, C. 



'79. Ueber der Entwicklung der Tellerschnecke. Morph. Jahrbuch, 

 Bd. V. Heft 4, pp. 562-655, Taf. XXXII.-XXXVIIL, 7 Holzsch. 

 1879. 

 The'el, H. 



'92. On the Development of Echinocyamus pusillus (O. F. Miil- 

 ler). Nova Acta Reg. Soc. Sc. Upsala, Ser. III. Vol. VI., 57 pp., 

 PI. 9. 1892. 



Wilson, E. B. 



'92. The Cell Lineage of Nereis. A Contribution to the Cytogeny 



of the Annelid Body. Jour. Morph., Vol VI. No. 3, pp. 361-480, 



PI. XIII.-XX. 

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Morph., Vol. VIIL No. 3, pp. 579-638, PI. XXIX.-XXXVIII. 



EXPLANATION OF PLATE I. 



Figures 1-4, Limax, drawn with camera lucida. 



Figure 1. Eight-cell stage from anterior end, X 375; p.g., polar globules; 

 s.c, segmentation cavity. 



" 2. Twenty-four-cell stage from right side, X 375. 



" 3. Twenty-five-cell stage from the animal pole, X 375. 



" 4. Same egg from vegetative pole, X 375. 



Figures 5, 6, Nereis after Wilson ('92). 



" 5 After Plate XIV. Fig. 21, " Rear view of twenty-two-cell stage. 

 Division of A', spindles of c s , d 3 ." 



" 6. After Plate XV. Fig. 25, " Thirty-two- (four-) cell stage, right side- 

 view. Third spiral cleavage of a 1 , b l , c 1 , d l , in progress." 



