the Development of Anableps Gronovii. 437 



it, to be visible. Externally, the sac is covered with what 

 appear to be parallel projecting lines, extending from the 

 sides of the abdomen to its most prominent part (Figs. 6 

 & 8.) These Valenciennes describes as " vascular strise, 5 ' 

 (stries vasculiformes.*) Such was not the nature of these 

 markings in the specimens which I examined ; but, when 

 placed under the microscope, were found to form a peculiar 

 structure, which possibly may have some connection with the 

 process of nutrition in their peculiar method of gestation. 



The sac itself seemed nearly homogeneous in structure, 

 but the strise are made up of spherical, or in some cases, pyri- 

 form or cylindrical, papillae or villi, (Fig. 8,) projecting from the 

 surface, and arranged so nearly together in a linear series as to 

 give the appearance of a continuous band. In regard to the 

 minute structure of these papillae, as far as it could be deter- 

 mined from an alcoholic specimen, they consist externally of 

 an exceedingly thin membrane, inclosing a vast number 

 of minute granules ; no vessels were seen in connection 

 with them nor in the membrane to which they were attached. 

 There was no appearance of any communication between the 

 cavity of the papilla and that of the membrane to which it was 

 attached. Within the latter, but more nearly in contact with 

 the intestines, there was a second more delicate membrane, 

 which seemed to be a continuation of the parietal peritoneum. 

 No traces of the yelk were found in connection with the 

 intestines. 



III. The third specimen is much longer and measures ten 

 inches in length ; the ovary had been ruptured, so that some 

 of the fetuses had escaped into the cavity of the abdomen, 

 but the whole number of young taken from the parent was 

 much greater than in the preceding case, namely, eighteen ; 

 one of these was projecting from the genital opening. They 

 generally resembled the preceding except in size, though the 

 eyes had become more prominent (Fig. 6,) and the iris now 



* Op. cit. ex fol. de planche, 539. 



