of Edinhurgh, Session 1883-84. 
5G7 
In his first paper, “iSTotes on British Tunicata,” published in 
1880, a suggestion is made as to the cause of the peculiar relations 
of the viscera in the genera Ascidia, Ciona, and Corella. Six new 
species are described, and several old ones are fully described for the 
first time, and their synonymy cleared uj). In subsequent papers f 
on British Ascidians, various other species are described, and he deals 
with individual variations in the Tunicata, traces changes in the 
branchial sac of Styela grossidaria^ showing the folds becoming 
obsolete and almost disappearing, discusses the variations of the 
dorsal tubercle within the limits of species, and tries to show how 
the various forms are connected, § 
In the last number of the Transactions there is a paper on the 
Tunicata of the Faroe Channel,’' in which the anatomy and 
histology of Doliolum is treated in great detail. 
The valuable collections made by the ‘‘Challenger” Expedition 
were placed in Professor Herdman’s hands for examination and 
description, and the preliminary notices of these were published in 
the Proceedings of this Society. In the first part of the final 
Memoir published in the “Challenger” series of Eeports, nine new 
genera and seventy -four new species are described. 
If we except the Molgulidge, which Lacaze-Duthiers discussed in 
1877, Professor Herdman was the first to fully define the families 
and sub-families of the Asddice Simplices. 
The anatomy and histology of the new and more remarkable 
deep-sea forms are described in great detail, the description of 
Cideolus murrayi being probably the most minute and detailed 
description of an Ascidian that has ever been published. 
In this memoir some remarkable structures are for the first time 
pointed out, — 1st, a system of branched calcareous spicules in the 
vessels of the branchial sac and endostyle \ 2nd, a curious modifica- 
tion of the blood-vessels in the test, which probably converts the 
outer layer of the latter into a respiratory organ. The family 
Clavelinidse is removed from the compound to the simple Ascidians, 
and reasons are given for this change in classification, and the Report 
concludes with a phylogenetic table. 
* Journ. Lhm. Soc. ZooL, vol. xv. p. 274. 
t Ibid., p. 329. t Proc. Lit. and Phil. Soc., Liverpool. 
§ Proc. Roy. Phys. Soc., Ediuburgli, 
