ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 613 



septemcarinata. It may be said that Passiphaea comes in between these 

 two species, and the forms described by Sars — Sderocrangon boreas, 

 Cryptocheles, and Bytliocaris — in which the metamorphosis is altogether 

 suppressed. 



Cirolanidae.* — E. G. Racovitza gives an account of these interesting 

 and primitive Isopods. He reviews their " palfeogenetic " characters : — 

 (1) Persistent traces of the groove which articulates the maxillipede- 

 segment to the head ; (2) first antennae with a rudiment of an accessory 

 flagellum ; (3) second antenna with a blade of six joints ; (4) first 

 pereionite with the epimero-tergal suture still visible ; (5) epiniera ii-vii 

 well developed and articulated to their somite ; (6) monomorphic 

 pereiopods all ambulatory : (7) pleon provided with five free somites ; 

 (8) sympodile of the pleopods with traces of several joints ; (9) pleopods 

 very uniform and equally well developed ; and (10) the absence of 

 sexual dimorphism. The genera Typliocirolana, Sphseromides, and 

 Faiicheria are dealt with. 



Annulata. 



Nervous System of Polychaets.f — Otto Storch has made an interest- 

 ing discovery in taking a comparative survey of the nervous systems of 

 Polychtets. In Hermoclke, one of the Amphinomidte, he has found two 

 pairs of nerve-cords extending backwards, a parapodial pair with ganglia 

 in addition to the ventral chain. He calls this the tetraneural as con- 

 trasted with the ordinary dineural type of nervous system. Perhaps the 

 dineural has been secondarily derived from the tetraneural. If the 

 oesophageal nerves of Hermodice be counted in, it may be said that there 

 are six longitudinal nerves, which brings the Annelids into line with 

 other Zygoneura, e.g. the Scolecida which have typically six, and the 

 Mollusca which have four or six. In the Articulata the dineural type 

 has prevailed. 



Development of Aricia foetida.J — Julius Schaxel has made a study 

 of the oogenesis, maturation, fertilization, segmentation, and organo- 

 genesis of this Polycha3t — all with special reference to cytology. His 

 chief aim has been to study the intracellular processes that go on during 

 morphogenesis. After his detailed description of what he has observed 

 to occur, he discusses the cytomorphological method, the factors in 

 development, the localization of hereditary substances (chromatin being 

 held as alone worthy of the name of inheritance-bearer), and the cell- 

 theory as modified by modern investigations. 



Minute Structure of Flabelligera.§ — Kurt Giinther has made a 

 study of the minute structure of Flahelliijera {Siphonostoma) diplochaitus 

 Otto, a marine Polychifit in the family Chlorhaemidaj, which is probably 

 intermediate between Terebellids and Serpulids. In the genus FlabeJU- 



* Arch. Zool. Exper., x. (1912) pp. 203-329 (14 pis.). 



t Verb. Zool. Bot. Ges. Wien, Ixii. (1912) pp. 81-97 (4 figs.). 



: Zool. Jahrb., xxxiv. (1912) pp. 381-472 (13 pis. and 10 figs.). 



§ Jen. Zeitscbr. Naturw., xlviii. (1912) pp. 93-186 (1 pi. and 55 figs.). 



