ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 433 



first myocccl. The "rostral episomite process" contains no special 

 " myomerite." The so-called first myomerite, which in young larva-, 

 extends without limitation in a long rostra] myomerite process, docs not 

 go so far forward in the fully formed animal, but ends about the cerebral 

 vesicle. From its anterior margin a long triangular anteriorly pointed 

 tendon is given off, which is attached to the median wall of the episo- 

 mite process. 



The first scleroccel extends oidy as far forward as the muscle ; it is 

 not only dorsally but also ventrally closed off from the myocad, being 

 only connected with it ventrally at the posterior end of the segment,. 

 At the anterior margin of other typical myomerites there arc tendon- 

 fibres which penetrate into the myoseptum in front. 



The last episomite gives off posteriorly on each side a, hollow "ter- 

 minal episomite process," extending laterally along the notochord. In 

 its median wall there is a delicate terminal tendon continued from the 

 last myomerite. The last myocoul is imperfectly separated from the 

 penultimate myoccel. 



Tunicata. 



New Genus of Synascidian.* — Asajiro Oka describes Aphambran- 

 chiou, a new genus of Synascidian from the coasts of .Japan. It is, 

 perhaps, to be regarded as within the family Distomidss, if the diagnosis 

 of the family is somewhat enlarged. The most striking peculiarity is 

 that the branchial sac is very degenerate and almost indistinct. The 

 thorax is so relatively minute that it appears simply as an inconspicuous 

 appendage at the anterior end of the well-developed abdomen. Extremely 

 small point-like apertures arranged in transverse rows represent the 

 branchial clefts, and there is no dorsal lamina. This interesting new 

 type is named Aphambranehion jcvponicum. 



Development of Diplosoma spongiforme.t — A. Pizon has studied 

 the complex phenomena of budding in this Diplosomid, which differ 

 in their sequence from those in 1). ILsteri. Particular attention is 

 directed to the singular process of visceral bipartition, which the author 

 calls " displanchtomy." 



INVERTEBRATA. 



Mollusca. 



«■ Cephalopoda. 



Eyes of Cephalopods.J— 0. Hess finds a very sensitive optic purple 

 in the retina of many genera, e.g. Loligo. It very closely resembles the 

 similar pigment in Vertebrates. In all cases the colour of the fresh 

 retina is brown to brownish -red ; the colour of the preserved retina 

 differs according to the illumination of the eye in the last hours of life. 

 Three stages in the differentiation of the (Vphalopod retina are dis- 

 tinguished : — (a) with uniform thickness and uniformly close rods (Loligo, 



* Annot. Zool. Japon, v. (1906) pp. 253-65 (1 pi.). 

 t Comptes RenduH, cxlii. (1906) pp. 463-5 (1 fig.). 



X Arch. ges. Physiol., cix. (1905) pp. 393-439 (4 pis.). Sec also Zool. Zontralbl., 

 xiii. (1906) pp. 192-3. 



