ZOB 



A BIOLOGICAL JOURNAL. 



Vol. III. OCTOBER, 1892. No. 3. 



BALANOGLOSSUS AS ONE OF THE GENERALIZED 

 TYPES IN ZOOLOGY.* 



With Plate xxii. 

 BY WILLIAM E. RITTER. 



During the summer of 1890, it was my good fortune to be able 

 to spend the vacation studying in Alexander Agassiz's Marine 

 Laboratory at Newport, R. I. While there I became greatly in- 

 terested in Balanoglossus and its larva, and collected considerable 

 material for its study, and the original drawings here presented 

 were made at that time. 



I take this opportunity to call the attention of our Pacific Coast 

 zoologists to this remarkable animal more particularly than the zo- 

 ological text-books and the special papers treating of it would be 

 likely to do, the desire being to hasten the bringing of the creature 

 to light if it exist on these shores. At the same time, however, I 

 will add a few observations and reflections of my own, that may not 

 be altogether without interest to those who have made a detailed 

 study of the animal. Since Kowalevski^ published the results of 

 his investigations on the development of the simple Ascidians in 

 1866, and there pointed out their relationship to the Vertebrates, 

 no animal has been brought into court that has given such weighty 

 testimony against the reality of a definite and hard fixed line sepa- 

 rating Vertebrates from Invertebrates, such as was supposed by the 

 older zoologists, as has this same wormlike Balanoglossus. 



The credit of having first recognized the true nature of the animal 



* Modified from a paper read before the California Zoological Club, San Fran- 

 cisco, March 26, 1892. 



'A. Kowalevski, Entwickelungsgeschichte der einfachen Ascidien. Mem. Acad. 

 Imp. Sci., St. P., viie ser. T. x, No. 15, 1866. 



