34 I^IILLETIN 41, UNITED STATES NATIONAL MUSEITM. 



1855. GiKARD, Charles — Contiuiu'd. 



"When mature, tlie eggs either fall into the space between the membranes or ovarian pouches, 

 or else remain attached to the ovaries until tlio embryos issue out of them. AVe are inclined 

 to think that they drop into the pouches as eggs. At any rate, we found very young embryos 

 loosely contained in the ovarian pouches, when no trace of the egg membrane could be seen 

 within the tissues of the ovaries in the shape of corpora lutei or graflftan vesicles. "Whatever 

 be the case, numerous eggs or embryos may be observed within one pouch. The young thus 

 remain together until grown to a considerable size, when, filling up the si)ace in a more com- 

 ]>act luannei-, the ovarian membranes, in their nature very expansive, will extend a fold be- 

 tween each embryo. In lias manner every individual young, when removed sideways from 

 the ovary, appears to the operator as if inclosed in a sei)arat(! cavity, pouch, or follicle of the 

 ovary, wliilst, in reality, the membranes may be stretched out or extended, and the entire 

 l)rogeny loosened from all adherence or connection with tliem. 



Tlie male organs of generation consist of two spermaries, a right and a left, perfectly inde- 

 pendent of each other, each having its separate duct, discharging their contents into an 

 elongated cloaca, into which the bladder likewise em])ties its contents. This cloaca commu- 

 nicates Avith the exterior by a subcircular opening, the edge of which is rather ]irotruding. 

 Such is that apparatus— the same in its general structure as in the other osseous fishes. 

 There is no sheath inclosing tlie two spermaries, and this fact tlirows a considerable light 

 upon the morphology of the ovaries, the latter being in fact two in number, but so closely 

 connected together as to simulate a single organ. Thus the general disposition, not the jilan 

 of structure, of these organs is adapted to tlie mode of reinoduction— a single sheath being a 

 more simple adaptation than two, one for each ovary. 



How the mechanical act of fecundation takes place w(^ are not prepared to say from direct 

 observations; the eggs themselves must be fecundated within the ovarian sheath; a copula- 

 tion of some sort is therefore required, and it is not improbable that at this period the eggs 

 have dropped fi-om the ovarian membranes into the pouches or spaces between tliese mem- 

 branes, in which they are freely floating. 



The hatching of the embryos takes place at an early period. After leaving the egg shell, 

 they liave an abdominal bag containing the remaining yolk, which is to be gi-adually alisorbed 

 during a period when neither the mouth nor the esophagus are fomied ; the fins liaving not yet 

 appeared. The visual organs begin with a dejjosition of an external layer of black pimentum, 

 in every respect similar to the same organs in invertebrata. The head is anteriorly rounded, 

 and the cleft of the mouth not yet apparent at the ]>eriod when the fins begin to develop. The 

 caudal has the start over -all other fins : its posterior margin is first lanceolated, then rounded, 

 with a convexity gradually diminishing until it is ])erfectly straight, when a gradual emargi- 

 nation commences, and from a slight crescent reaches tlie forked sliajie which it assumes in 

 the adult. The soft and articulated portion of the dorsal and anal fins next assume a devel- 

 opment reaching extraordinary portions, which they again gradually lose as soon as free from 

 parental sheltering. The posterior portion of these fins is especially to be noticed, being longer 

 and deeper than the anterior jiortion (the reverse of what we observe in the adult, ) and extend- 

 ing generally beyond the base of the caudal fin, a character, therefore, not ex<lu8ively ju'oper 

 to the genus Rhacocheilus. Tlie spinous portions of these same fins, on the other liand, devclo]) 

 .slowly and gradually, reaching their full growth at a late period. The ventrals and pec- 

 torals are likewise tardy in their appearance. The scales are fully developed liefore tlie young 

 leave the ovary. 



ICmbiotoca. Agass .S20 



Embiotoca Jacksoni, Agass .'520 



Siin Francisco, Dr. A. L. Heerniium. 



Embiotoca Cassidi, Grd ;!20 



San Diego, California, Lieut. "W. P. Trowliridge, IT. s. A. 



Embiotoca Webbi, n. s 320 



San Diego, California, Lieut, "W. P. Trowbridge, T'. S, A. 



/■Embiotoca lineata. Grd ;!20 



San rrancisco Bay, Dr. A. L. Heermann. 



Embiotoca ornata, n. s .321 



San Diego, California, Lieut. W". P. Trowbridge, V. S. A. 



Embiotoca perspicabilis. n. s 321 



Puget Sound, Dr. Geo. Suckley, IT. S. A. 



Damai.ichtuys, n. g 321 



Dainalichtlii/s vacca, u. s 321 



I'uget Sirand, Dr. Geo. Suckley, 1^. S. .\ . 



I'HANERODON, Girard 321 



I'hanarodon furcatun, Grd 322 



San Francisco Bav, Lieut, W. P. Trowbridge. I', S. .V, . 



