438 Wyman's Observations on 



exhibited its lateral projections sufficiently developed to give 

 the pupil the shape of a dumb-bell. The umbilical sac has 

 become much larger than in the embryos first described, and 

 measures three eighths of an inch in diameter. The papillae 

 of the yelk-sac are much more distinct and contain colored 

 granules. The yelk-sac communicates with the cavity of the 

 abdomen by a long fissure extending from a point just behind 

 the union of the opercula nearly as far as the anal opening, 

 consequently beyond the ventral fins. It is from the circum- 

 stance just mentioned, doubtless, that an explanation is to be 

 found of the non-union of the ventrals in the adult. The 

 scales terminate abruptly at the edge of the fissure. The 

 intestines, as in the first described embryos, were invested by 

 the internal sac, which was regarded as parietal peritoneum. 

 No bands were visible on the flanks of the body nor were the 

 anal fins yet modified to mark the sexes. A rudimentary 

 liver is visible in these specimens, extending backwards on 

 the left side of the intestinal mass. The intestinal canal is of 

 almost uniform size throughout, there being no distinction 

 between intestine and stomach. 



IV. This specimen measured a little less than ten inches 

 in length, but the embryos were of much larger size, having a 

 length of two and a quarter inches ; the umbilical sac had 

 disappeared, (Fig. 7,) but the fissure on the under side of the 

 abdomen still remained, and what seems quite remarkable, 

 had grown in dimensions just in proportion to the entire 

 foetus, so that in these specimens it measured one inch in 

 length, and was consequently longer than the whole embryo 

 of the first specimen noticed above. The edges of the fissure 

 were united by the intermedium of a thin membrane, without 

 scales, on which no papillae were noticed, and was suffi- 

 ciently lax to allow the edges of the fissure to separate from 

 each other to a slight extent. The transverse band upon the 

 cornea was now distinct, though it had not yet become as 

 opaque as in the adult. 



Seven foetuses were found in the ovary ; on the sides of 



