276 IXPLANATION OF 



PLATE III. 



Fig, 1. Crista trici/ttara, p. 61. 



a. A branch, of the natural size. 



B. The fore part of an articulation, magnified. 



C. The back. 



2. Acamarchis Neritina, p. 58. 



a. A branch, of the natural size. 

 B. A fragment of a magnified branch, shown in 

 the back. 



3. Acamarchis dentata^ p. 59. 



a. A branch, of the natural size. 

 B. Fragment of a magnified branch, seen in 

 front. 

 Nota. In B, Fig. 1, as well as B, fig. 3, are shown many 

 cells which have lost their upper membrane. 



4. Menipea Hyalcea, p. 63. 



a. A branch, of the natural size. 



B. Cell magnified, seen in front. 



C. Ditto, seen in the back. 



D. Cells magnified, seen sidewise. 

 5 Eucratea chelata, p. 64. 



a. The fragment of a branch, magnified. 



6. JEtea anguina, p. 65. 



a. Fragment of a branch magnified, with the 

 cells in various positions. 



7. Pasithea tulipifera, p. 67. 



a. Fragment of a branch, magnified. 



8. Pasithea quadridentata, p. 67. 



a. Fragment of a branch, magnified. 



B. Ovarium transversely striated, and magnified. 



