PEROPHORA. 197 



the ganglion, dorsal tubercle, peri-pharyngeal bands, oral tentacles, 

 anterior portion of the endostyle, dorsal lamina, etc.). 

 Make drawings that will show the structure. 



Hunter: Notes on the Heart Action of Molgula manhattensis. Am. Jour. 



PhysioL, 10, 1903. 

 Kingsley: Some Points in the Development of Molgula. Proc. Bost. Soc. 



Nat. Hist., 21, 1883. 

 Van Name: Simple Ascidians. Proc. Bost. Soc. Nat. Hist., 34, 1912. 



PEROPHORA. 



This ascidian occurs on piles and other submerged materials, 

 and is commonly attached by branching stolons to seaweeds, 

 simple tunicates, or other sessile animals. Material should be 

 quite fresh for satisfactory study, and should be carefully 

 handled to avoid crushing. Study in a watch-glass of sea- 

 water (or support the cover-glass) with a low power of the mi- 

 croscope. 



1. Notice that the individuals are very much like miniature 

 Molgulas. Identify as many of the organs that were seen in 

 Molgula as possible, noting the differences. 



2. The form illustrates the type (Clavelinidse) in which a 

 colony is formed by budding from a stolon, but in which the 

 individuals retain their identity to a great degree and have sepa- 

 rate tunics. 



3. Study the stolon with its flattened epicardiac tube. This 

 tube is derived from the branchial sac and is accordingly endo- 

 dermic. 



4. Study buds of various sizes and see how the inner vesicles 

 arise from the epicardiac tube. 



5. Try to make out the entire course of the circulation of the 

 blood. Notice especially the heart, branchial vessels, vessels of 

 the mantle, and the circulation of the stolon. Watch the pulsa- 

 tions of the heart and see the reversal of the blood-current. Is 

 the heart-beat synchronous in different individuals? What part 

 of the blood is colored? 



6. Study the action of the cilia in the gill clefts. 

 Drawings of a colony and of an individual are desirable. 



Lefevre: Budding in Perophora. Jour. Morph., 14, 1898. 



