Anatomical Notes on the ' Comet* ' of 



Linclda muUifora, Lamarck. 



by 



S. Hirola. 



(With Plate XI.) 



During the last thirty years, various modes of regeneration have been 

 observed among Starfishes by numerous authors. A summary of the facts 

 bearing on the subject, as ekicidated by early writers was given in 1884 

 by Martens,^^^ and only a single newst has since been informed by the 

 Sarasin brothers/-^ 



Of all the modes of regeneration, the formation of the comet-shaped 

 young from a fallen arm is known as the most important in LincMa and a 

 few others, although in the latter a fuller demonstration is still needed. As 

 far as I know, no observer has, however, had an opportunity to dissect a 

 ' comet ' and to examine its interior organs which are in the course of 

 regeneration, but confined himself to an inquiry of the external features. 



When I lived, the last year, on the Bonin Islands, for a few months, 

 I gathered a number of Linchia muUifora on coral reefs along the coast. I 

 brought home thirty-nine speciemens of this species, a majority of which 

 possess an arm or arms partly or wholly regenerated, and of which two 

 are typical ' comets '. At that time, I gathered them, however, simply for 

 exhibition in the Zoological Museum and my speciemens are therefore too 



* I use the term 'comet' for the german ' Kometenform ' which signifies the comet-shaped 

 young of some starfishes. 



t That an arm may be furcated in its distal portion or even may form a secondary star, 

 R. Semen illustrated in the 'Jena. Zeit. fiir Xaturwiss. Bd. 23.' an example of Opldopsila aranea, 

 in which the disc is formed in the middle of a broken arm, but the s-rme example seems, accord- 

 ing to H. Ludwig (Zool. Anz. Jahrg. 12.) to be a normal form, partially regenerated. 



