On the Habits of the Japanese Lingula,.* 



BY 



Naohidé Yatsu, 



The present short notes are published as a supplement to the 

 cecological observations of the previous writers, such as Morse, Semper, 

 and François. But before entering into the habits I shall touch upon 

 the distribution and the specific characters of the Japanese Lingula. 



From Japanese waters five species of Lingula have been described. 

 They have however, been declared by Davidson to be varieties of one 

 and the same species (Lischke 'GÜ p. 115). Whether this view is a 

 correct one I cannot at present determine, since as yet I have not had the 

 opportunity of examining materials from various localities in Japan. In 

 the museum of the Zoological Institute there are specimens from 

 Misaki, Hyakkan-zeki (Kyushü), and the islands of Bizen. Of these 

 localities the second yields very large specimens and those of slightly 

 different features from those collected at any other localities. At any 

 rate all the specimens I have examined tally with Lingula ematina 

 Brug. 



Blochmann ('00. p. D4-D5) enumerates several distinguishing 

 characteristics of Lingula anati na Brug from Lingula murphiana 

 King. Of these only the mode of branching of the palliai sinus seems 

 to be a reliable criterion, all others being mere individual differences. In 

 the specimens examined by me, the peduncle, for exmple, in some in- 

 dividuals terminates in an ampulla, while in others from one and 

 the same locality it ends in solid attenuated cuticle. Some gape a little 

 in the posterior part of the shell, while in others the shells are closed 

 firmly all around the margins. Proportions of length, breadth and 



* This formed a part of my graduating thesis, but, as it lias less connection with my 

 embriologica] studies. I have thought it best to make it a separate paper. 



