462 Report of the State Geolog-ist. 



the lophophore (fig. 22, g). It gives forth a band which runs 

 along the root of the lophophore toward the back (fig. 22, A), giv- 

 ing off a branch to each tentacle, continuing on the arms to the 

 extremity, giving off branches to each tentacle on the outer 

 margin of the arms ; turning at the extremity in its backward 

 course it gives off branches to each tentacle on the inner side of 

 the arms. The ganglion also sends forth a filament which imme- 

 diately enters the substance of the oesophagus, probably supply- 

 ing the mouth, epistome and oesophagus, but it has been traced 

 for only a short distance. 



Ebproductive Organs. 



The ovary and testes occur in the same cell. In certain sea- 

 sons of the year the ovary may be seen attached by a short 

 peduncle to the endocyst a short distance below the mouth of 

 the cell (Plate A, figs. 1, 2, p). It is a rounded mass composed 

 of ova in various stages of growth. The testes are situated on 

 the funiculus, below the fundus of the stomach (Plate A, 5), and 

 are developed in the form of an irregular mass. It is formed of 

 spherical cells, each of which contains a second cell, which devel- 

 ops into a spermatozoidal filament, escaping by the rupture of 

 the cell. They have a distinct but somewhat sluggish, undulat- 

 ing movement. They are carried about the perigastric space by 

 the current and thus come in contact with the ova. They were 

 observed in 1837 by Dr. Farre, but were mistaken for parasites. 



There are three methods of reproduction, first by the true ova, 

 developing. into a free ciliated embryo; secondly, by gemmation^ 

 and thirdly, in the Hippocrepian forms by statoblasts, the 

 nature of which will be hereafter described. 



The process of gemmation may be observed with comparative 

 ease in Paludicella, and is illustrated by figure 26. In the 

 earliest stages in which the " bud has been noticed, it consists of 

 a slight tubercle on the parent cell, <z, filled with parenchyma. 

 It soon becomes elongated and has a cavity communicating with 

 the parent cell, h. In g it has increased in size and consists of an 

 external envelope continuous with the ectocyst of the parent 

 cell, and a thick lining continuous with the endocyst and con- 

 taining numerous round, nucleated cells. These two features 

 develop into the ectocyst and endocyst of the adult cell. In d 



