AXJTHOB 8 ABSTRACT OP THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE, NOVEMBER 7 



AMAROUCIUM CONSTELLATUM (VERRILL)i 



II. THE STRUCTURE AND ORGANIZATION OF THE TADPOLE 

 LARVA 



CASWELL GRAVE 



Washington University, St. Louis, Missouri 



POUR TEXT FIGURES AND FOUR PLATES 



This paper, which deals with the structural organization of 

 the fully developed tadpole larva of Amaroucium constellatum, 

 is a contribution, in part, to the morphology of ascidians, but it 

 is especially intended as a further contribution toward the estab- 

 lishment of a basis for a comparative study of the larval forms 

 of a number of species of ascidian common to the Woods Hole 

 region with a view to the correlation, so far as may be possible, 

 of their specific structural and physiological characters with 

 observable differences in the distribution and habitat of each 

 species. 



The structures common to ascidian larvae in general have 

 been so repeatedly described in the many excellent papers pub- 

 lished during the fifty years that followed the announcement by 

 Kowalewsky ('66) of his discovery of the chordate affinities of 

 ascidians, that it seems unnecessary to attempt to cite specific 

 references to papers except in connection with results or con- 

 clusions that have not found general acceptance. The points 

 added to the morphologj'- of the ascidian larva as a result of 

 this study are enumerated in the concluding paragraphs of the 

 paper. 



1 Since the publication of the first paper of this series (Grave, '20 b) con- 

 clusive evidence has been secured that Amaroucium constellatum is not a form 

 of A. pellucidum, but must be considered a true species, hence the change in 

 the general title for this, the second paper. The systematic data referred to 

 will constitute the subject matter of a special paper. 



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JOURNAL OF MORPHOLOGY, VOL. 36, NO. 1 



