94 



DEPARTMEyr OF THE XAYAL SERVICE 



Es. An anterior group of four muscle bands. A posterior group of two muscle 

 bands. Muscle just behind peripharyngeal band diverging from it 

 dorsally. S. fusiformis gregai. 



Aj. Muscles of the body foi'ming oomplete rings. On each side a row of slit-like stig- 



DolioUdae. 



mata. 



Body barrel-shaped or cylindrical. 8 or 9 muscle bands. 



Doliolum. 



Hj. Nine muscle bands. Oozooid. 



H... Eight muscle bands. Other stages. 



Stigmata beginning at second band above and ending just behind 

 fourth band below. D. nationalis. 



Salpidae. — The salpae occur frequently in chains of individuals, which are readily 

 broken up. These individuals (proles gregata) alternate with those of another kind 

 (proles solitaria), which are always found singly. The two differ markedly in structure. 



Salpa fusiformis Cuv., forma aspera Chamisso. 

 1912. Ihle, p. 39. 



C.G.S. Acadia. 



This species is widely distributed through all the warmer seas and is carried 

 by currents into the colder waters. Of all the Salpae that are carried into the north 

 Atlantic by the Gulf Stream, S. fusiformis goes the farthest. It is apparently better able 

 to endure the lowered temperature and salinity than the remaining species. It was the 

 most abundant Salpa of our cruises and was the only one to occur at more than one 

 station. Bigelow obtained it in the gulf of Maine on August 14 and 15, 1912 (1914, p. 

 121) and south of cape Cod in July, 1913 (1915, p. 275). On the European coast it 

 appears regularly during the course of each summer,' passing into the English Channel 

 and north of the British isles to the coast of Norway and into the Skager Rak (Ap- 

 stein, 1911, p. 151). 



Five Salpae in a bad state of preservation but apparently belonging to this species 

 are before me. They were obtained on the beach at Campobello island in th"fe autumn of 

 1913 and sent in by Captain Shepard Mitchell. They are from 33 to 35 mm. in length. 



Salpa vagfina (Tilesius) proles gregata (=^tilesii). 

 1912. Ihle, p. 47. 



C.G.S. Acadia. 



This species is widely dietributed but not found in abundance. It is rare in the 

 north. Bigelow obtained it i-n July, 1913, south of Cape Cod (1915, p. 275), and in 



