VISCEEAL ANATOMY OF THE CEARACIXID.E. 



75 



in the absence of any communication, between tlie ovarian tract and the general body- 

 eavity, and in the continuation of the ovarian membranes to form a common duct 

 to the exterior. 



In some of the other Characinids in which ovaries were found, these organs appeared 

 to coalesce at a point anterior to the anus, and to continue to the exterior as a common 

 mass of ripe ova. Some such appearance I observed in Fetersiits and Micralesles. 

 This condition I interpret as being referable to the Alestes-ij])Q; for obviously, if in 

 Alestes the common oviducal space were crammed with ripe ova in transit, the 

 appearance of the whole apparatus would be suggestive of an early coalescence of 

 the ovaries themselves. In the Erythrinoid form Lebiasiiia, also, there was tlie 

 appearance of coalescence, but beginning furtlier back, about the level of the anus ; 

 also, but still further restricted to the posterior portion, in Tetragonopterus abramis. 

 In all these instances of apparently coalesced ovaries the investing membranes them- 

 selves were not recognizably present, but the indications seemed to me to demand their 

 existence. 



It w^ill be observed that tlie ovarian relations above described present no resemblance 

 to those existing in Amia, in which the ova fall freely into the body-cavity, and thence 

 pass by wide orifices into the oviducal funnels. 



The testes seem to be of the normal Teleostean type, presenting no features worthy 

 of remark. They are seen as narrow bands, arising at the sides of the anteriot chamber 

 of the air-bladder, and passing back uniformly to their junction just before opening 

 to the exterior. 



The Kidneys. 



The kidneys in my specimens have not, generally speaking, been well preserved, and 

 I have no minute observations to record. It may, however, be stated that these organs 

 in the Characinidse extend for the whole length of the body-cavity, from near the 

 diaphragm backwards immediately under the vertebral column. In some cases there 

 seemed to be an anterior enlargement ('• head-kidney " ?) in which the anterior end of 

 the air-bladder was more or less imbedded. Xo enclosure in muscle was observed. 



The Heart. 



I carefully examined the heart in one of my largest specimens, Jlacrodou, for signs 

 of a valvular conus. No valves, however, were found to exist, beyond the two small 

 pockets at the exit of the ventricle and that guarding the auriculo-ventricular aperture. 



The Mespiratory Organs. 



Concerning the respiratory organs, I liave as yet no new observation to record. Tlie 

 gills themselves seem to present no special features. There is, however, in certain of the 

 Charaoinidse an accessory branchial organ, arising as a blind sac from the upper margin 



