Botany and Zoology. 421 



portant zoological periodical is published. It is edited by Pro- 

 fessors Leuckart and Chun and they propose to devote this new 

 serial to more elaborate monographs than can from their size or 

 the number of their illustrations easily find a place in zoological 

 periodicals. The Bibliotheca Zoologica will hold in zoology very 

 much the same place which Palseontographica and similar publi- 

 cations hold in pala?ontology. The first number contains a most 

 interesting monograph on the existence of a pelagic fauna at 

 great depth and its relation to the surface pelagic fauna. Dr. 

 Chun was engaged upon a monograph of so-called deep-sea 

 Siphonophorae' collected by Chierchia during the voyage of the 

 '* Vettor Pisani." Though collected on the sounding line they 

 were labelled with the utmost precision as living below 1000 

 meters. Chun who was also preparing a monograph of the 

 Mediterranean Siphonophores came to the conclusion that the 

 collection of Chierchia supported the views of Studer that peculiar 

 Siphonophores formed an important part of a pelagic deep-sea 

 fauna. Under the auspices of the Zoological Station at Naples 

 he carried on most successful deep-sea tow net experiments 

 from August to October, 1866. Unfortunately this expedition, 

 interesting as its results are, does little toward settling the sub- 

 jects under discussion because neither the distance from shore 

 nor the depths investigated were great enough to eliminate the 

 disturbing effects of close proximity to land ; as it was near the 

 continental slope, on the very edge of which Dr. Chun trawled 

 with the tow net. The results are further vitiated from the 

 fact that they have been carried on in a closed sea where the 

 conditions of temperature are strikingly different from those 

 of the Atlantic, and where at a depth of about 500 fathoms we find 

 already the lowest temperatures of the deepest part of the Medi- 

 terranean. The minimum seasonal differences of temperature 

 between that and the surface cannot be contrasted to oceanic 

 conditions. 



Dr. Chun made use for his investigations of an ingenious self- 

 closing tow net invented by Captain Palumbo of the " Vettor 

 Pisani." It may be closed at any given point by means of a pro- 

 pell or working in a rectangular frame attached to the tow net on 

 the same principle as the propellor for upsetting the Negretti 

 Zambra deep-sea thermometer and the Sigsbee water bottle. 

 The little steamer " Johannes Mtiller " of the Naples Zoological 

 Station made an excursion to the Ponza Islands as well as expe- 

 ditions to the Gulf of Salerno, to Ischia and Ventotene. 



The contents of the deep-sea tow nets used by the Challenger 

 could not be assigned to any definite depth as the nets were not 

 closed either on the descent or the ascent. Neither can the 

 method adopted on the "Blake" of collecting at intermediate 

 depths by means of the Sigsbee collecting cylinder be considered 

 decisive. It had not been tried long enough or frequently enough 

 at great depths (it was not carried beyond 150. fathoms) to decide 

 the depth to which the surface pelagic fauna might sink or to 



