﻿92 54 



we find the opening of the two large veins from the pectoral fins, which in Am- 

 phisile ran into the large trunk of the V. hepalica. 



The swim-bladder (s) extends from over the oesophagus to over the anter- 

 ior end of the genital organs; it is provided with a very similar horseshoe-shaped 

 "rete mirabile" to that found in Amphisile, asymmetrical as in that form with the 

 right horn a little shorter than the left. 



The kidneys (re) are fused together posteriorly to a fairly large, triangular, 

 compressed mass, which is bounded behind by the long, hæmal spine of the first 

 caudal vertebra; it is penetrated by the short, hæmal spines on the last two abdo- 

 minal vertebrae; anteriorly, dorsally to the swim-bladder, it divides into two thin- 

 ner tracts along each of the cardinal veins, broadening somewhat in the intei'- 

 spaces between the transverse processes of the elongated vertebræ; above the ante- 

 rior end of the swim-bladder it widens out on each side into a considerable 

 "head-kidney" (re'), which even extends forward beyond the trunk under the skull; 

 it is pierced by the nerves for the pectoral fins. The narrow part of the kidney 

 lying under the spinal column here contains canaliculi; these are wanting however 

 in the front portion, so far as I have seen. A urinary bladder seems also to be 

 wanting here. 



Genital organs. The ovaries (go) are only confinent in the posterior half, 

 the first half being free; the common oviduct lies as usual dorsally to the rectum. 

 The ovarial lamellæ are placed transversely. P'rom the anterior end of the ovary 

 a large vein runs along the free margin of the mesoarium to the Ductus Cuvieri. 



I have not seen the testes; the 4 specimens dissected by me were all females ^^. 



Notes. 



Amphisile. 

 1; p. 51 (13): 



The cxoskelelon in Amphisile lias tjcen mentioned, it need hardly be said, in all descrip- 

 tions of the species right from the earliest; hitherto, liowever, all the statements regarding 

 it have kepi to what could be seen directly from tlic outside of the fish and oven tlie most 

 complete descriptions contain errors. Whilst the dorsal armour could hardly escape atten- 

 tion, the ventral armour with its much thinner and weaker parts has often been quite over- 

 looked or — not least in recent years — (juite misundcrstoo<l. Linnk (23a, p. 336) brought 

 together in concise form tlie essential points known in liis time regarding this genus; tor the 

 genus Cenlriscus {= Am]>hi.'iilein) Klein) he names only thej dorsal armour: "Corpus dorso 

 loricatum", for the species Csculatus likewise: "Singularis piscis loricatus testa ossea longi- 

 tudinali postice in spinam terminata, sub qua cauda". This is repeated in Ed. XII (23b, 

 p. 415) (where however the diagnosis of the genus is altered owing to the inclusion of the 



