242 CHORDATA 



(c) The adhesive organs. How many are there? 



(d) The notochord. How far does it extend? 



(e) The tail muscles. 



(/) The pharynx, with as yet few gill clefts, the en- 

 dostyle, esophagus, stomach, intestine, and yolk mass, 

 (g) The cerebral vesicle with the eye spot and otolith. 



If young individuals that have been attached but a short 

 time, but have lost their tails, are stained and mounted, they 

 will be found very instructive when compared with the larva. 

 The complete degeneration of the tail and the final rotation 

 into the position of the adult can be traced in a series of in- 

 dividuals. 



Drawings of an adult individual, of a larva, and of a 

 young individual are desirable. 



van Name: Compound Ascidians of the Coasts of New England and 

 Neighboring Provinces. Proc. Bost. Soc. Nat. Hist., 34, 1910. 



SALPA CORDIFORMIS 



Examine a specimen in a bowl of water without dissect- 

 ing. Use a hand lens. 



Sexual form (occurring in chains) : 



1. Note the transverse muscle bands. How many bands 

 are there? Are they complete or interrupted? Do you know 

 what they are for? 



2. The oral aperture is dorsal and far forward. Are there 

 any muscles for opening and closing it? 



3. What is the form and position of the cloacal aperture? 

 Is it provided with muscles? 



4. Observe the processes of the tunic, one anterior, one 

 midventral and two posterior. These processes (except the 

 dorsal posterior) serve to unite the individuals of the chain. 



5. Does the animal show perfect bilateral symmetry? 



6. Posterior to the mouth, the ganglion and the pigmented 

 eye spot may be found. Immediately anterior to these is 

 the elongate hypophysis. 



