78 ME. W. S. EOWNTEEE ON THE 



(9) The CLaracinid stomach is witli or without a blind sac. The cardiac and pyloric 

 regions are well differentiated. In the herbivorous forms the pyloric portion is highly 

 muscular and gizzard- like. The pyloric flexure is usually directed ventrally, but in 

 some forms is fairly constantly turned in some other direction. 



(10) Pyloric cteca are always present in the Characinidse, but in very varying number 

 and development. They sometimes fringe the intestine for a considerable distance. 



(11) The length of the intestine in the carnivorous Characinids does not exceed the 

 body-length, and is usually less. In the herbivorous and mud-eating forms it is very 

 much longer, varying from about twice to five times the length of the fish. It may vary 

 also in calibre in different regions. No trace of a spiral valve was observed. 



(12) The liver in the Characinida3 is usually tri-lobed, the proportionate development 

 of the three lobes being very variable. In some forms one or more of the lobes may be 

 greatly elongated, or may be much reduced. The gall-bladder is usually attached to the 

 right lobe. 



(13) The African Characinid Sarcodaces strikingly resembles the Erythrinoid 

 Characinids, not only in cranial characters, as shown by Sagemehl, but also in certain 

 visceral characters, notably in the opening of the ductus pneumaticus far to the left on 

 the alimentary canal, in the character of the ovaries, and in the features of the air- 

 bladder. 



(14) The herbivorous Characinids, more especially Dtstichodiis, Xenocharax, and 

 Citharinus, resemble one another in the marked thickening of the sheet of peritoneum 

 which shuts off the air-bladder from the body-cavity. In all the distinguishing visceral 

 characters of this group, Xenocliarax s,eeYa.s, to present a lower stage of specialization than 

 the other two associated forms. 



(15) In the structural features of the air-bladder, Serrasalmo and Anacyrtus seem to 

 be separately and somewhat widely divergent from the other Characinids. 



(16) If the ridging of the posterior air-bladder be regarded as having a vestigial 

 significance, the Characinidse, Cyprinida?, and Gymnotidse would seem to represent 

 successive stages of air-bladder evolution. 



(17) With the possible exception of the indications of a cellular air-bladder, there 

 appears to be nothing in the visceral anatomy of the Characinidse which strengthens the 

 deductions made from the skull as to the Amioid affinities of the group. In opposition 

 to such deductions are especially the cystoarian ovaries, the asymmetric ductus 

 pneumaticus, the presence of pyloric appendages, and the absence of all trace of a 

 valvular conus and of an intestinal spiral valve. 



