930 I UK METAMORPHOSIS OF BOLINA CHUNI, 



BOLINA CHUNI. Nov. spec. 



Body slightly compressed. Lobes when expanded about as long 

 as the body. Surface smooth. Auricels long and triangular with 

 straight sides and a sharp-pointed end. Bulges above the nerve- 

 center high, paddles not large and rather numerous. Adradial 

 canals join the proximal part of Meridional vessels. Curves of the 

 lobe-vessels simple. 



Size : Length 11 Cm., breadth of lobes 9 Cm. 



Colour: Perfectly transparent. Lobe-vessels in the adult violet. 



The most striking feature of this Bolina is the great bulk of the 

 lobes, which ai'e thicker than the body, and nearly circular. The 

 lobe- vessels are extremely simple and show the characteristic 

 arabese-shaped curves only when the lobe is contracted. The 

 muscles in the lobe are clearly visible forming an extremely delicate 

 network of radial and circular fibres, which however, are by no means 

 so distinct as those in Eucharis multicornis. The body appears in 

 its upper end decidedly truncate. The stomach is rectangular and 

 much broader than in other species. 



The sense organ is situated about 1 Cm., below the aboral end 

 of the body. 



The specific name needs no explanation. 



DEVELOPMENT. 



The youngest Bolina Chuni, which I obtained was a globular 

 larva with about 3 mm., in diameter. (Fig. 3). Decidedly pear- 

 shaped it differs from the larvae figured by Agassiz and Chun in 

 shape very much, as the narrow part is the oral, whilst the broad 

 part, the aboral end of the animal. 



The sense organ lies more than half way below the aboral 

 end of the body, a peculiarity which is met with in very much 

 younger larvae of Eucharis and Bolina alata. I have mentioned 

 before that the transverse section of this, as well as of later stages, 

 is circular. It appears that the larva of Eucharis is compressed 

 in another direction than the adult animal. (Chun I.e., p. 1 - - . ) 

 Agassiz (I.e., p. 15) states that Bolina is compressed in the same 

 direction throughout. It appeals, therefore, that this character is 

 ted to greater changes than has been supposed. 



