ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 241 



of the larva and adult is formed by the elongation of that part of the 

 gastrula body situated behind or within the circumblastoporal ring. 

 In Molluscs, however, the ventral surface grows out to form the foot, 

 the dorsal surface developes a shell, while the whole animal remains 

 relatively short and the resulting form is very different from the 

 Annelid. 



Anatomy of the Serpulea with Characteristics of Australian 

 Species.* — W. A. Haswell gives the results of observations on the 

 Serpulea of Port Jackson, including representatives of all the prin- 

 cipal subdivisions of the group, which differ very little from their 

 European allies. Two points in the anatomy are specially dwelt on : 

 (1) the pseudohaemal system, and (2) the segmental organs and 

 " tubiparous glands." The segmental organs in Eupomatus elegans 

 serve not only as efferent ducts for the generative products, but also 

 as seats of development of the ova. 



The following species are described : — Eupomatus elegans, Cymo- 

 spira hrachycera, 0. morchii, Pomatostegus bowerhanJci, Pomatoceros 

 elaphus, Vennilia strigiceps, V. ccespitosa, V. rosea, Serpula vasifera 

 n. sp., S. jukesii, Salmacina australis n. sp., Sahella velata n. sp., 

 S. punctulata n. sp., SpirograpMs australensis n. sp. 



' Metamorphosis of Nephelis.f — R. S. Bergh finds that in 

 Nephelis, just as Aulostomum, the provisional body- wall (ectoderm and 

 musculature) is cast off, and the whole of the body, with the exception 

 of the epithelium of the mesenteron, is built up from the fused head- 

 and trunk-germs. Eathke seized on the truth as to the development 

 of Aulostomum and Nephelis, but his results have been ignored by suc- 

 ceeding writers, who have all described it as being simple and direct ; 

 Semper alone recognized the head-germ and found that it gave rise 

 not only to the cerebrum, but also to connective tissue and mus- 

 culatui'e. 



The primitive kidneys bud out, in early stages of development, 

 from 'the trunk-germs, which are still separated from one another by 

 a wide interspace. While the earlier stages are as in Aulostomum, differ- 

 ences are to be observed in the character of the fully developed organs ; 

 for in Neplielis each may.be divided into two primary parts, which may 

 be known as ring and duct ; in Aulostomum (and in Hirudo) the ring is 

 alone present. In all the three genera the primitive kidneys are 

 completely devoid of any orifices ; the duct is formed of a single canal, 

 the ring of two, which partly coil around one another. In some cases, 

 however, it seems to be clear that the existence of two canals is only 

 apparent, and that each archinephric ring consists of a single canal, 

 which arises from the duct, is, so to speak, rolled up, and ends 

 blindly. 



With regard to the other processes of metamorphosis, Bergh states 

 that the primitive ectoderm forms a single layer of flattened cells, the 

 boundaries between which are apparent only in early stages ; later on 

 the cells become flattened out and their limits disappear. The mus- 



* Proc. Linn. Soc. N. S. Wales, ix. (1884) pp. 649-75 (5 pis.), 

 t Zeitschr. f. Wiss. Zool., sli. (1884) pp. 284-301 (2 pis.). 

 Ser. 2.— Vol. V. r 



