SOME PUGET SOUND ASCIDIANS. 599 



The close correspondence in internal structure between this 

 species and C. viacrosipJiomis naturally suggests the possibility 

 that the two may in reality be but strongly marked variations of 

 the same species, but the external differences are so great, not 

 only in form and proportions, but also in texture of the test, that 

 it hardly seems possible that they are not distinct species, and it 

 is probable that further study of ample material will discover dis- 

 tinctive characters other than those now apparent. 



C. erecta is undoubtedly a very close ally to C. dura Heller. 

 From the accounts of the internal structure to C. dura as given 

 by Heller, '77, and Traustedt, '83, I am unable to find any dis- 

 tinctions that would warrant the recognition of a separate species 

 for my specimen. The external characters appear, however, to 

 be very different. C. dura is a strongly depressed species, it 

 never being even in young individuals where the form is, accor- 

 ding to Heller " mehr rundlich," as high as broad. Again, ac- 

 cording to both Heller and Traustedt, the test of C. dura is veiy 

 hard and much tuberculated over the entire surface. 



Cynthia castaneiformis von Drasche. 

 (PI. XVni., Figs. 6 and 7, and PI. XIX., Fig. 25.) . 



Cynthia castaneiformis Drasche, '84, p. 373. 



Cynthia castaneiformis Traustedt, '84, p. 27, 



I identify this as von Drasche's species with some hesitation, 

 von Drasche, however, made his description from a single spec- 

 men, and that a rather small one, hence probably an immature 

 one. I therefore conclude that the discrepancies between his 

 description and my observations are due to the insufficiency of 

 specimens at his command. 



The peduncle is described and figured as being as long as the 

 body. In some individuals this is true ; in others, however, the 

 peduncle is longer than the body, and in still others it is shorter. 

 The orifices are said to be " sitzend." In most preserved speci- 

 mens they are so, but in life they are not (Figs. 6 and 7) ; they 

 are quite prominent and are turned toward each other. In de- 

 scribing the processes of the test, the author makes no mention of 



