101« 



SCANDINAVIAN FISIIKS. 



folds. Beside the tcniiiiuitioii of tlic stcjiiiach thf in- 

 testine forms a curve of varying size, with one or more 

 small convolutions, before passing into the rectum, from 

 wliich it is divided intcriialh' In' ;i inort^ or less distinct, 

 annuhii' fold". Tiie liver is generally almost entire, 

 having only a more or less deep incision in tin; hind 

 margin. Its length is about ' , of that of the abdomi- 

 nal cavity proper, somewhat more than '^ of that of 

 the stomach, (jr ' j of tiie distance between the termi- 

 nation of the stomach and the vent. Sometimes, how- 

 ever, its length is equal to the last-mentioned distance. 

 Its upper, concave side surrounds the under side of the 

 oesophagus and the begiiming of the stomach, as well 

 as the gall-bladder, which is rather large and lies to 

 the right. The spleen is oblong, rather more than half 

 as long as the liver, and is situated on the right side, 

 at the fold between the ])vl<irus and the intestine. On 

 " 1 1 



and MA(irii'' as testes. The air-ljladder varies consider- 

 abl)' in length, between ' ^, and ' 3 of that of the alj- 

 dominal cavity proper. It is of a pointed fusiform 

 shape, lint in front, for almost half its length, is divided 

 into ;in upper and a lower cone, the latter joined by 

 the piicuniatir duct to the oesophagus, tliough in the 

 s])ecimens examined by us the communication has in- 

 variably been closed. The kidneys lie, as usual, close 

 below the spinal column, above the air-bladder and 

 vvithout the peritoneal cavity. They extend not only 

 throughout the length of the abdominal cavity proper, 

 l)ut also int(j the backward continuation of the hieinal 

 canal, in the caudal region, above the prolongations of 

 the abdominal cavity, to which structures we shall re- 

 turn in our description of the generative organs. The 

 urinary bladder lies just behind the downward curve 

 of tlie rectum towards the vent, and has its orifice just 



M 



Fig. 272. Alidoiuinal visuera <.f Amjuilla Bnlgan.<. After SvitsKi. A. female; /;, male. 

 A: a, riglit, i, left ovary; c. right, d. left prolongation of the ovary in the eauilo-alnlominal cavity; e. septum (prolongation of tlic mesen- 

 tery) between the cauclo-abdominal cavities; /, vent; (/. urinary bladder; //, fold of ailipose membrane on the right side of the intestine; //', 

 fold of adipose membrane on the stomach; i, fold of adipose membrane on tlie left side; k. stomach; /, pylorus; m. liver; 



n, gall-bladder; 0, pectoral fins. 

 B: rt, right, 6, left testis; c, right, d, left prolongation of the testis in tlie caiido-ahduminal cavity; e, septum between the caudo-abdoininal 

 cavities;/, efferent duct of the testes {ous deferms); g, seminal vesicle; li. vent; /. urinary bladder, mainly concealed by the seminal vesicle; 

 /■, k', and I, corresponding to li. h' , and / in .-1 (see above); m, stomach; n. pylorus: o, liver, turned up to show how it is applied to the 



(esophagus and stomach; ;), gall-ldadder; i/. pectoral fins. 



the left side of this fold, tis well ;is <m Ijoth sides of 

 the intestine and rectum, liangs a lolmlnted peritoneal 

 fold, whicli has been develojjed into an omentum-like 



behind the tuial aperture. In our c()mnion Eel it has 

 the form of an equilateral triangle, with one angle (the 

 so-called neck) directed downwards and passing into 



fold of adipose membrane, 'consisting of coiniective-tissue : the urogenitnl a})erture. 



meshes tilled with fat-globules. In appearance these 

 folds are so like generative organs that they have been 

 described both by Ercolani'' and by Balsaiio-Cravci.li 



of tl 



" The honeycombed mucous mend)rai 

 ])art, is apparently subject to considerable variations. 

 ' Mem. Accad. Sc. Bologna, 1872, p. 529. 

 '■ Mem. Isl. L(,nd.. Sc, Lett. AHlauo, Xll, 1872, p. 229 



The generative organs are suspended on each side 

 of the abdominal cavit)- and throughout the greater 

 part of its length, side liy side with and caitside the 



intestine and rectum, as well as tlio tliiekiiess of their walls and tliat (jf the pyloric 



