ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 29 



calcareous spicules of the epidermis are imbedded in a cuticle of great 

 strength, and chitinous in character. The spines are in all cases 

 obtusely acicular. In the ventral wall of the pharynx there is a small 

 slit-shaped orifice, which leads into a short saccule, and in this there 

 is formed a small but very distinct radula. This organ, just as much 

 as the salivary glands, which are found in this new genus, is absent 

 from Neomenia. 



There are distinct signs of the presence of an organ of Bojanus in 

 the formation, near the anus, of a glandular body, which is traversed 

 by ciliated canals, and is found to contain black concretions. Some of 

 these canals appear to have, in addition, internal orifices. To the 

 right and left of the anus there is yet another glandular organ, which 

 is enclosed in a quantity of muscle. Masses of fine fibres, which 

 appear to be secreted by this double gland, lead to the hypothesis that 

 we have here the representation of the byssus-gland. 



Dr. Hubrecht promises further details as to this creature, of which 

 two specimens were dredged by Dr. Sluiter in Barents Sea. They 

 measure respectively 105 and 148 mm. 



Molluscoida. 



Tunicata of the 'Challenger' Expedition.* — The Tunicata of 

 this expedition have been confided to Dr. Herdmann, whose preliminary 

 report is now issued. He states that the entire collection contains 

 from 150 to 200 species, the majority of which are new to science. 



Dealing first with the Ascidiadse, or simple Ascidians, in which (1) 

 the body is sessile and attached, (2) the branchial aperture eight- and 

 the atrial aperture six-lobed, (3) the test gelatinous or cartilaginous, 

 (4) the branchial sac ordinarily papillated, and (5) with unbranched 

 filiform tentacles. He finds that of the already known genera .two 

 (Bhopalcea and Bhodosoma) are not represented. On the other hand, 

 there is a new genus, Abyssascidia, and a new sub-genus (of Ascidia), 

 Pachychloena. 



Abyssascidia has about twelve lobes to the branchial and eight to 

 the atrial aperture. The branchial sac is not longitudinally plicated ; 

 the viscera are on the right side of the branchial sac ; the intestine is 

 small, the stomach short and wide. Only one species is as yet known 

 — A. Wyvillii — which was taken at a depth of 2600 fathoms in the seas 

 south of Australia. Dr. Herdmann is of opinion that this new form 

 has relations to Ascidia and to Corella. The sub-genus Pachychlaena 

 has a very thick and solid test. The species ranged under it are 

 P. ohlonga, P. ohesa, P. gigantea. The other new species described in 

 this paper are Ciona Flemingii, Ascidia meridionalis, A. vasculosa, 

 A. translucida, A. tenera, A. pyriformis, A. falcigera, and Corella 

 japonica. A table indicating the affinities and characters of the 

 known species is given. 



In a second communication t Dr. Herdmann describes Ascidia 

 cylindracea, A. despecta, and A. placenta as new species, and then pro- 

 ceeds to an account of the Clavelinidce, which family, like many of the 



* Proc. Koy. Soc. Edin., 1879-80, p. 458. f Ibid., p. 714. 



