378 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Busk, He says that tlie pores in one section of the group have a totally 

 distinct morphological significance, and have possibly also a different 

 function from that of the other. He proposes to refer to the Microporel- 

 licla3 that division of the Adeonidfe which exhibits the zooecial structure 

 characteristic of the genus Acleona, and this is the view of Prof. Smitt. 

 With regard to the question of dividing the genus Adeona, it is remarked 

 that there is no element of structure among the Polyzoa so liable to 

 adaptive modifications as the so-called radical appendages, and Mr. Hincks 

 thinks that the species may well be ranged under the two heads of (1) 

 w'th a flexible stem and (commonly) fenestrate zoarium, and (2) without a 

 flexible stem. 



Treating of the Membraniporidte the author discusses his species 

 3Iembranipora radicifera, and has some notes on the genera. The family 

 characters of the Microporidse are defined, as are also those of the Stegano- 

 porcllidae ; this last contains at present three genera, the third of which — 

 Tlialamoporella — is new. 



' Challenger ' Polyzoa.* — The late Mr. G. Busk's second report on the 

 Polyzoa of the ' Challenger' treats of the Cyclostomata, Ctenostomata, and 

 Pedicellinea ; forty-six species are enumerated, of which thirteen appear to 

 be new. The Pedicellinea are represented by Ascopodaria fruticosa and 

 A. discreta ; Mr. Busk gives his reasons for preferring his generic name to 

 Barentsia or Pedicellinopsis. 



Key to the Fresh-water Polyzoa.t — A useful analytical key to the 

 known species of fresh-water Polyzoa, with figures, is published in the 

 journal noted at foot. It is based on Dr. J. Jullien's ' Monographie des 

 Bryozoaires d'eau douce.* 



Fresh-water Bryozoa.| — Dr. W. Eeinhard repels the accusation of 

 Herr Ostroumoff that in his account of the metamorphosis of Alcyonella 

 fungosa he only describes pathological processes. He confirmed the 

 observations of ^Nitsche, and as to what he has added to them with regard 

 to a special appendage there is no question of pathological change. Herr 

 A. Ostroumofl" has a reply to these criticisms.§ 



Arthropoda. 



Classification of the Arthropoda.|| — Prof. E. Eay Lankester publishes 

 a further answer to Prof. Claus, in which he repeats his statement that 

 what Prof. Claus announced as novelties had been formulated by him five 

 years i^reviously, and he discusses the explanations given by Prof. Claus. 



Digestive Tract of Arthropoda, and particularly of Insects.^ — Prof. A. 

 Schneider has discovered that the tunica propria which underlies the 

 endodermal cells of the midgut of Arthropods, consists of chitin. Where the 

 foregut of insects is united with the midgut there is a remarkable, and as yet 

 unnoticed, arrangement of the longitudinal fibres ; they arise behind the 

 middle of the foregut and become separated from the intestine, a part only 

 being inserted behind the commencement of the midgut ; this must cause 

 an invagination of the foregut, and so lead to the formation of a proboscis 

 which leads to various structures ; it may be simple or lobed, or beset with 

 setae and teeth, and so on. The proboscis is of some size in the larvae and 



* Reports of the Voyage of H.M.S. ' Cliallengcr,' 1. (1886) 47 pp. and 10 pis. 

 t Jomn. Trenton (N..T.) Nat. Hist. Soc, 1887, pp. 59-67 (I pi.). 

 X Zuol. Anzeig., x. (1887) pj). 19-20. § Tom. cit., pp. 168-9. 



II Ann. itnd Mag. Nat. Hist., xix. (1887) pp. 225-7. 

 ^ Zool. Anzeig., x. (1887) pp. 139-10. 



