ANATOMY — PHYliOGENY. 
Tun, 3 
A general account of the anatomy of Pyrosoma , Doliolum, Salpa, 
Octacnemus , and Appendicularia are given in the ‘ Challenger ’ Report, 
while detailed descriptions of some special points are found under the 
new species. 
Todaro (11 ) compares the two large branchial clefts of Salpa with 
the two stigmata of Appendicularia , and with the two primary stigmata 
of Ascidia. 
Physiology. 
Giard (2) lias found symbiotic fungi belonging to the Chytrulinew, and 
for which he has formed the new genus Nephromyces, living in the closed 
renal sac of some Molgulidce, at Wimereux. He finds distinct species of 
fungi in the Ascidians Molgula socialis, Aid., Litkonephrya eugyranda , 
Lac.-Duth., and Anurella roscovitana, Lac.-Duth. ; and he considers that 
these parasites are useful to their hosts by using up the excreted urinary 
products which otherwise might fill up the renal organ, which has no 
duct to the exterior. 
Parona (10) treats of the Protista parasitic iu Ciona intestinalis found 
at Genoa. 
Development. 
The late M. L. Joliet left an unfinished account of the structure and 
budding of Pyrosoma giganteum , which has now been published. He 
found that the subneural gland and its duct are derived, not from an 
invagination of the buccal cavity, but from the primitive neural vesicle. 
He believed the dorsal tubercle to be an olfactory organ. He discussed 
also, in another incomplete paper, the alternation of generations in 
Salpa and Pyrosoma , and defended Chamisso’s views against the objec- 
tions raised by Brooks. 
Geographical Distribution. 
The third and concluding part of the Report upon the ‘Challenger’ 
Tunicata contains an account of the geographical and bathymetrical 
distribution of the Thaliacea, the Panacea, and the Ascidice Salpiformes 
collected during the expedition. These lists show that the pelagic 
Tunicata are very widely distributed ; in fact, some species are seen to 
have a world-wide distribution, and no genus is restricted in its range to 
a particular ocean. The only undoubtedly deep-sea form is Octacnemus , 
which was probably fixed to the bottom. It was found at depths of 1070 
and 21 GO faths. 
PHYLOGENY. 
Lahille (8) considers that the Tunicata are not the ancestors of the 
Vertebrata , but form a very distinct group. 
Herdman (4), at the conclusion of the ‘ Challenger ’ Report, gives a 
detailed account of the probable phylogeny of the genera of the Tunicata. 
The group is regarded as a degenerate offshoot from the Protochordata, 
