TUNICATA. 
Moll 103 
to that side, the muscles of which are much more developed. Concern- 
ing the muscles and these orifices, there is no other difference than that 
of right and left, the same as between any object and its reflection in a 
mirror ; but as regards the intestine, the difference between right and 
left is accompanied by differences in the relative situation of the stomach, 
which lies more below when the intestine deviates to the left, and more 
above when it deviates to the right ; this may be termed rather a true 
shifting (forskydning) than a mere asymmetry. The author thinks that 
an asymmetrical fixation of the larva is the first cause of the asymmetry 
in the muscles ; and that this asymmetry in the muscles may cause the 
deviation of the intestine. Vid. Medd. 1881, pp. 257-268. 
The most important morphological peculiarity found in the deep-water 
Ascidians is the very remarkable condition of the branchial sac in the 
genera Culeolus , Fungulus , and Bathyoncus ; stigmata are apparently not 
formed in consequence of the suppression of the fine interstigmatic 
vessels ; the author thinks that really there is a double row of laterally 
placed stigmata, running transversely in place of longitudinally, and that 
this is not a primitive surviving form of the sac, but an after modification 
of a more complicated type. A very notable feature is also the presence 
of large blood- vesicles and hollow papillae in the test of Culeolus murrayi , 
which may be an accessory respiratory apparatus ; in others, the terminal 
branches of the blood-vessels are prolonged into hair-like processes of 
the test, for attaching foreign bodies so as to form a continuous protect- 
ing and concealing coat ; this is the case in the Molgulidce generally, in 
Polycarpa molguloides among the Cynthiidce , and in Ascidia conchitega 
among the Ascidiidce. Calcareous spicula are present iu several species 
of Culeolus and Cynthia : in the former, they are smooth, irregularly 
branched, and placed in the walls of the endostyle and the branchial sac, 
and in the tentacles, the dorsal lamina, and other organs ; in Cynthia , they 
are minutely echinated, simply rod-shaped or fusiform, and occur in the 
test, the mantle, and in the vessels of the branchial sac. The stomach and 
intestine vary considerably throughout the Ascidiidce in their relation to 
the branchial sac ; the simplest and central arrangement seems to be that 
which prevails in Ciona, where the oesophagus continues the antero- 
posterior line of the brauchial sac, and thus throws the stomach and the 
first part of the intestine- behind the brauchial sac. Iu Ascidia and 
Pachychlama, the stomach and intestino are placod on the loft side of the 
brauchial sac ; in Corynascidia , Abyssascidia , and most distinctly in 
Corella, on the right side. The author attributes these changes to a 
posterior prolongation of the branchial sac in one or the other direction, 
the stomach and intestine remaining comparatively passive. Herdman, 
Tunicata of the ‘ Challenger,’ pp. 275-285. 
Phylogenetic table of the Ascidice simplices ; id. 1. c. p. 286. 
Molgulidjd. 
General observations on this family; id. l.c. pp. 58-61. 
Molgula ccepiformis , sp. n., Sorby & Herdman, P. L. S. xvi. p. 533, 
pi. xi. figs. 1-8, Hoolen Bay, S. England. 
