W. G. VanJVame — Bermuda Ascidians. 331 



A few species are seldom to be fouiul along the shove, but grow 

 chiefly on the corals, sponges, gorgonians, etc, on the reefs or in 

 water deep enough to escape the effect of the waves and tides. 

 These were obtained in collecting the corals and gorgonians by 

 diving or by means of the nippers, attached to a long pole, which 

 are used for that jiurpose. 



Rhodozona plcta (Verrill), Distoma olivaceum, Cystodytes dra- 

 schii Herdman, Distaplla hermudensis, Amaroucium bermudoe, A. 

 exile, and Botrylloides nigrum var. concolor are among the forms 

 which are partial to such situations. 



As far as I know, no ascidians are to be found on the white shell 

 sand which covers large areas of the bottom in the sounds and har- 

 bors about the islands. So rough and rocky is the bottom in most 

 other places that but little dredging was done, and this did not add 

 any new forms to the list of tunicates. 



It is possible that in the vicinity of the outer reefs there may be 

 bottoms where a dredge can be used to advantage, and would proba- 

 bly disclose the existence of other species, particulai-ly of the Poly- 

 clinidse, which are partial to deeper water and are but poorly repre- 

 sented in our collections. Moreover, owing to the strong winds 

 and rough water prevailing during the sj^ring season (when all the 

 collections were made), no collecting was done on the outer reefs. 

 As many forms of invertebrates occur there which are seldom found 

 on the I'eefs near shore, there are probably other kinds of ascidians 

 there also. 



Note. — The names of places, given as the localities where the 

 specimens were found, are those of places about the Bermuda 

 Islands, unless otherwise stated. 



Methods of Preservation and Study. 



Most of the specimens were preserved in formalin of from 2 to 4 

 per cent. This preserves the form and to some extent the color of 

 the specimens better than any other method, but for anatomical 

 study alcoholic specimens are usually better, though more contracted. 



The specimens Avere studied microscopically by dissecting out the 

 zooids or parts and staining and clearing in glycerine ; also by 

 means of paraffin sections of the zooids, or of the colonies, or parts 

 of the same. Generally the specimens must first be decalcified. 

 Owing to the absence of silicious sand at Bermuda, no trouble was 

 met with in cutting the sections. 



