93.] 0VERSIGT OVER NORGES ASCIDIAE SIMPLICES. 



91 



The tentacles are long and fine, about 50—60 and of 3 

 åes. The dorsal tubercle small,, almost only crescent shape; 

 \q horus not rolled in. The wide opening between thems 

 t rn forward (fig. 3). The nerveganglie is situated abont 3 mm. 

 Ihind the dorsal tubercle, equal to from Vio to V12 of the 

 hgth of the body (inside measure). 



, The dorsal fold is ribbed on the left side and runs a piece 

 lyond the swallow; the edge is strongly dentated; a high, 

 l,nt tooth on each bar, and generally a little one between. 



The branchial sack stretches a little behind the intestinal 

 cial, and the hindmost is rather obtusely cut off ; it is rather 

 songly folded. On the fine internal logitudinal bars, high 

 pillæ sit upon the crossing points with the transverse arteries, 

 vich papillæ, on the side, exhibit the usual spoon shape, 

 le intermediary papillæ very seldom appear and are then 

 s all conical. 



The meshes generally about quadrate, with about 5 (3 — 7) 

 o ong, elliptical, spiracles. In the first variety, the branchial 

 s;k is finer, and the whole animale thinner, and more trans 

 p/ent, than in the latter, the spiracles are also fewer in each 

 nsh, viz. 3 — 4 which are nearly rectilinear. 



The swallow lies a little distance (about 5 mm.) from the 

 h dmost part of the branchial sack, in an oblong, elliptical 

 nsh, and has a flat lip on each side. On the right side of 

 ti swallow, single, large processes, which sometimes have 

 c.v r en point. E^ophagus narrow and bent. Stomach round. 

 T 3 gut makes a not very strong twist (fig. 2) in this respect 

 is ust between A. obliqua, Aid. and A. complanata, Fabr. The 

 a:.is is situated somewhat lower than the gut twist, free, the 

 e<;e is thick, bent down and divided into several (5) un- 

 e< ally large lips, which again, by crossing furrows, are divided 

 ir ) smaller partions (fig. 5) ; this is in the first variety ; in the 

 sond the gut is much thicker and more swollen; the gut- 

 r ^st is higher, and the anus therefore seems to be situated 

 lo er (fig. 46). All this is the result of a strong development 

 °1 he kidney concrements, and the genital organs in the gut- 



