2 Tun, 
tunicata. 
13. Maurice, C. Notes sur VAmarceciiim torquatum. Arch. Z. exp^r. 
2® s6r. iv, pp. xxvi-xxxii. 
14. . Sur l’appareil branchial, les systemes nerveux et musculairede 
VAmarceciiim torquatum. C.R. ciii, pp. 434-436. 
15. . Sur la cceur, le tube digestif et les organes genitaux de 
VAmarcccium torquatum. T. c. pp. 504-506. 
16. Nansen, F. Forelobig Meddelelse om Undersogelser over Central- 
nervesystemets histologiske Bygninghos Ascidierne samt hos Myxine 
glutinosa. Bergens Mus. Aarsber. f. 1885, pp. 55-78. 
17. Roule, L. Sur quelques variations iudividuelles de structure des 
Organes chez les Ascidies simples. C.R. cii. pp. 831-833. 
18. . Sur quelques peculiarity histologiques du tube digestif des 
Ascidies simples, &c. Op. cit. No. 25, pp. 1503-1506. 
19. .' Revision des especes de Phallusiad^es des cotes de Provence. 
Rec. Z. Suisse, iii, No. 2, pp. 209-259, pis. xii-xv. 
20. . Recherches sur les Ascidies simples des cdtes de Provence. 
Ann. Sci. Nat. (6) Zool. xx. pp. 1-229, pis. i-xiii. 
21. Swederus, M. B. Tunikater frau Sibiriens Ishaf och Berings Haf, 
&c. Yega. Exped. Vetensk. Jakttag. 4 Bd. pp. 87-112. 
Anatomy. 
He rdm an (4), as an introduction to the description of the new 1 Chal- 
lenger ’ species, gives a general account, illustrated by diagrams, of the ana- 
tomy and histology of the Compound Ascidiaus. A more detailod account 
of the structure of certain special forms (particularly the genus Colella) 
is given in the body of the report. One of the most remarkable forms is 
the deep-sea species, Pharyngodictyon mirabile , in which the branchial 
sac is in the same degenerate condition as in Culeolus, amongst Simple 
Ascidians. It has large meshes, with no true stigmata, and apparently no 
cilia. A number of species were found to have their ascidiozooids pro- 
togynous ( i.e. } female when young, and male only when full grown). 
Roule (17) finds as an individual variation in Cynthia papilla sa, L 
and Ascidia elongata , Roule, the same condition of the duct from the 
eubneural gland as is found normally in Ascidia mammillata , Cuv., and 
Ascidia marioni, Roule, viz., the presence of more than one external 
aperture. 
The walls of the. alimentary canal in the Cynthiidce contain, according 
to Roule (18), a closed system of delicate tubes, the larger branches of 
which anastomose, while the finer twigs terminate in ovoid ampullae. 
They are grouped mainly around the blood lacunae ; they do not com- 
municate either with the exterior or with the lumen of the alimentary 
canal, and they enclose granules which give the murexide reaction. Roule 
considers that they are renal in function, and correspond to the closed 
renal vesicles of the Ascidiidce. ... 
In continuation of his researches on the Simple Ascidians of the coast of 
