Miscellaneous. 341 



speedily died in confinement, he was unable to make continuous 

 observations upon them in a living state. Of the results of his 

 observations he gives the following summary : — 



" The fish stands to the star-fish in a definite relation which cannot 

 be the subject of observation. Why the little fish should always seek 

 the stomachal cavity of one and the same species of star-fish, and not 

 that of various species, is a mystery. It is well known that Crustaceans 

 of the genus Pagurus inhabit the empty shells of Mollusca ; but we 

 find on the shore the same species of Pagurus in the shells of the 

 most various genera and species. I have never met with Oxybeles 

 gracilis, on the contrary, in any other species of star-fish than Cul- 

 cita discoidea *." The fish was described by Bleeker under the 

 above name in * Natuurkundig Tijdschrift,' vii. p. 162. The author 

 proceeds to state that neither he nor any one else in Amboyna has 

 ever captured the fish under other circumstances, or while swimming 

 freely in the sea ; but upon this Dr. Bleeker remarks that many of 

 liis specimens of Fierasfer Brandesii, and all those of Fierasfer 

 {Oxybeles) gracilis and F. lumbricoides, were obtained by him along 

 with other fishes, and were probably taken while swimming freely in 

 the sea. 



Upon the habits of Oxybeles gracilis the author goes on to say 

 that it is certain tliat this animal passes the greater part of its exist- 

 ence in the stomach of the star-fish, raiely showing itself outside of 

 this, and then probably at night. That it does come out occasionally, 

 appears from the fact that in two cases the author observed the fish 

 with a portion of its body outside the cavity of the star-fish, and in 

 the act of creeping in. The same observations showed that the fish, 

 in returning to its concealment, passes along the furrow of the lower 

 surface of one of the arms leading to the mouth of the star-fish, which 

 is wide enough, when the tentacles are retracted, to leave room for 

 the passage of the slender body of the Oxybeles. This fact likewise 

 proves tliat the Oxybeles does not get into the stomach of the Culcita 

 by accident. 



If a living Culcita be cut in two, the fish is seen moving freely in 

 the cavity of its body. If it be taken out, it immediately seeks the 

 shade. If the two halves of the Culcita (still alive) be placed in the 

 water, the fish will soon be seen to draw towards them, in order to 

 get into the cavity of the star-fish. When exposed to the light, it is 

 uneasy, and its iris contracts excessively. The author never found 

 two fishes in the same star-fish. 



In most of the fishes examined by him, the author found the sto- 

 mach empty ; it was full only in one. The contents cf the stomach 

 had the ap|)earance of a lump of fat, and consisted of half-digested 

 muscle. Under the microscope, striated muscular fibres could be 

 detected ; and the author thinks that they belonged to the muscles of 

 a fish. This circumstance proves that Oxybeles does not feed upon 

 the chyle of the star-fish, but that its nourishment is analogous to 



* Fierasfer Brandesii, or Oxybeles Brandesii, Blkr., inhabits not only 

 Culcita discoidea, but also several species of Trepang, such as Tripang 

 edulis and T. onavja*.— Note by Dr. Bleeker. 



