Chaetognaths of Misaki Harbor. 

 By T. Aida. 



Zoological Institute, Science College, Imp. Univ., Tokyo. 

 With PL ttl. Sf one wood-cut. 



During the frequent visits made to the Marine Zoological Station of 

 the Imperial University at Misaki for the last two years, I have 

 devoted myself specially to the collection of the chaetognaths to be 

 found in the harbor. Up to date, I have been able to collect twelve 

 species in all. The majority of these can not, however, be fished at all 

 seasons of the year, as their presence depends a great deal on current and 

 wind. For instance, late in summer last year, when an offshoot of the 

 Great Black Stream (kuroshiwo) swept into the harbor, many species 

 not to be seen at other times were caught. I do not therefore think 

 that the list here given is by any means exhaustive. Other species will 

 no doubt be added hereafter from time to time. 



Of the twelve species mentioned below, four I believe to be new to 

 science. I have adopted the classification of Langerhans (1), as it 

 appears most convenient to me. 



]. Sagitta bipunctata, Quoy et Gaiinard. 

 (Fig. f.) 



Literature: Langerhans (1), Hertwio (2), Grassi (3), Strodtmann (1). 

 The specimens which I refer to this species present characters 

 agreeing essentially with the descriptions given by the authors cited 

 above, the agreement being especially noticeable in the position and 

 size of the fins, the thickness of the epidermis, the form and position of 

 the corona ciliata, the length of the body and its ratio to the length of 

 the caudal segment, the size of the ovaries, and a few other points. But 



