110 Moll . 
MOLLDSCOIDEA. 
sists of a small cellular mass eventually surrounding the principal portion 
of the polypide, of which it will form no more than the musculo-con- 
nective appendages ; the essential part or epithelial lamella of the future 
polypide is here furnished entirely by the invagination of the ab-oral 
surface. In the adult Bryozoon, the author distinguishes from these data 
three surfaces : (1) the foot, corresponding to the oral pole, (2) the frontal 
surface, corresponding to the surface, which answers to the mouth, and 
(3) the tergal surface, corresponding to the anus, the two latter surfaces 
both forming parts of the ab-oral surface, which forms the entire integu- 
ment ; these three surfaces are easily recognized in the Endoprocta , and 
among the Ectoprocta in forms such as Serialaria , JJugula , &c. ; in those 
forms which are spread out into a plate, such as Escharina and the ma- 
jority of the Chilostomata, it is the tergal face whose growth always gives 
origin to the first bud. Finally, the author puts forwards the hypothesis 
that the Polyzoa may be derived by adaptation to sessile life from swim- 
ming organisms, free and probably analogous to the Rotifera, of which the 
few known larvse of Endoprocta represent the sole survivors. J. de l’Anat. 
Phys. 1882, pp. 1-34; translated Ann.N. H. (5) x. pp. 265-279 & 388-403, 
pi. xiv. ; abstract in J. R. Micr. Soc. (2) ii. pp. 492-494. 
Notes on the origin and development of the sexual products in the 
chilostome Polyzoa by W. J. Vigelius, Biol. Centralbl. ii. pp. 436-442. 
Popular description of the development of the Polyzoa by 0. Taschen- 
berg, Yerwandlungen der Thiere, 1882, pp. 154-156. 
In the ubiquitous Microporella ciliata (Pall.), the following forms of the 
avicularian organ occur: (1) Ordinary avicularium with pointed beak; 
(2) avicularium with the mandible elongated into a spine ; (3) avicula- 
rium with the spinous mandible supporting a membranous flapper ; (4) 
vibraculoid structure with tall well-developed seta and partially modified 
beak. Hence may be concluded that avicularium and vibraculum are 
the same organ, differently modified. Iliucks, Anu. N. II. (5) ix. pp. 
20-23, woodcuts. 
W. A. HASWELLhas observed a Cellepora } from Torres Straits, having 
minute Actinids scattered over its branches and occupying the terminal 
portions of narrow canals in the substance of the bryozoarium ; P. Linn. 
Soc. N. S. W., Nov. 1882. 
H. Allen remarks on the tenacity of life exhibited by Plumatella 
vesicularia , Leidy, the growth of which was not interfered with by the 
presence of oxide of iron in the water ; P. Ac. Philad. 1882, p. 223. 
Fresh-water Polyzoa. 
Bohemia. 1 Cristatella , 1 Alcyonella , 2 Plumatella , 1 Fredericella , and 
an undetermined species enumerated and described with some woodcuts 
by J. Kafka, SB. bohm. Ges. 1881, pp. 250-254. 
Marine Polyzoa. 
27 species, including 1 new, collected during the cruises of the Dutch 
steamer, ‘Willem Barents,' in the Arctic Sea, enumerated by W. J. Vige- 
lius, Niederl. Arch. Zool. Suppl. i. pt. 3, 20 pp. 1 pi. 
