74 THE CYPRINODONTS. 



the bend is to the left. The canal for urine and sperm lies on the short, 

 concave side of the bend whether to right or left. These peculiarities obtain 

 in each of the species of the genus. Turning to the females of -4. aiiahleps we 

 find a large scale to cover the opening to ureters and ovary. This scale may 

 be called a shutter, a foricula ; it is unattached at one side or the other so as 

 to open to the right on some individuals or to the left on others (Plate VII. 

 Fig. 1, 4, 5). Thirty-four females of this species have the shutter free to open 

 to the left, while on twenty-one others it opens to the.right. From all this we 

 must conclude that in Anableps the individuals of the sexes are rights and 

 lefts, dextral or sinistral. Nearly three fifths of the males were rights, as we 

 have seen above ; these naturally would couple with females that were lefts, 

 in support of which we find about three fifths of those in this collection to 

 have the shutter opening to the left side. On one male of A. microlejns the 

 anal bends to the right, on another to the left. The female of this species 

 apparently has not the large scale for a .shutter that is seen on A. aiiahlejjs, 

 but the opening is situated in a groove or fold of which the scales of one side 

 overlap those of the other. Two of these females are lefts, and two are 

 rights. Of three males of A. Dowii two are rights ; one is a left. The shut- 

 ter of the female Dowii is like that of A. microlepis. The anal of the male 

 Anableps differs from that of other Cyprinodonts, excepting Jenynsia, in 

 that the canal extends the entire length of the rays. 



The egg of Anableps differs from that of allied Cyprinodonts mainly in 

 the contained amount of nutriment for the embryo, in addition to the yelk. 

 Very young embryos have particles of the yelk in the bag with the intes- 

 tines. The albuminous matter is great in amount, and, wholly or in part, 

 usually lies in contact with the papillae on the outside of the sac, the hard- 

 ened masses (in alcohol) showing the indentations of the series. On Plate 

 VI. Fig. 2, 4, the letter lo indicates the positions of the albumen on a couple 

 of embryos. The papillae of the bag do not fit into pits on the inside of the 

 general envelope of the egg ; in fact, few if any of them come in contact 

 with the investing membrane, as is evident from the position assumed by 

 the embryo around its bag (Fig. 2, 3). The embryo has freedom of move- 

 ment ; it is not attached to the egg coverings by the bag. The amount of 

 albumen to be found within the egg decreases as the embryos enlarge; and, 

 comparatively, the papillae are larger on the younger specimens. The series 

 of papilla? mark the courses of the blood vessels into which they pour the 

 material ab.sorbed. The arrangement and connections of the vessels are sug- 



