42 CTENOPHORES OF THE ATLANTIC COAST OF NORTH AMERICA 



There are numerous excretory pores along the courses of the merid- 

 ional vessels (fig. 59, plate 11). These alternate with and open between 

 the combs of cilia, and also open along the lines of the 4 meridional 

 subventral canals over the oral lobes below the oral ends of the rows 

 of combs. These pores contain a brilliant rosin-red oily substance 

 which is cast out if the animal be handled roughly or be suddenly 

 disturbed, forming a fluorescent-looking, rosin-red cloud in the water 

 surrounding the ctenophore. When maintained in an aquarium the ani- 

 mal soon loses all of this red pigment and becomes quite transparent and 

 inconspicuous, but in nature its 8 long rows of brilliant red dots render 

 it most beautiful and conspicuous. We can only conjecture that this 

 red substance is of an excretory nature and may possibly serve as a 

 means of protection. 



The lateral branches of the 2 paragastric canals are bordered by 

 a row of tentacles, all of which are simple and short, except the median 

 tentacle, which has many short, simple side branches. 



The muscular system in the oral lobes is well developed and the 

 lobes commonly overlap. This ctenophore moves wholly by means of 

 its ciliated combs. It is extremely soft in texture and a strong current 

 in the water suffices to tear its tissues. Indeed, I have seen it only when 

 the ocean has been tmrippled for a day or more, after which it may be 

 found swimming near the surface at sunrise. A slight ripple causes it 

 to sink out of sight. It was fairly common during May, 1906, at Tor- 

 tugas, Florida, but all of them were found more than 3 miles from land, 

 and apparently it is a creature of the deep and open sea. 



Eurhamphcea appears to be very rare in the Mediterranean. Gegen- 

 baur foimd only two specimens, both in a single day in February at 

 Messina, and Chun found it only once in March, 1875, during the course 

 of his five years' study of Mediterranean ctenophoras at Naples. At 

 Tortugas it is rare and occasional, but seems to occur in swarms when 

 foimd. I have not seen it later in the year than May. Fol describes 

 and figures it from the Canary Islands. 



Jonescu gives the latest description and figures of this ctenophore, 

 having foimd it at Naples in March, 1907. 



According to Fol, 1869, the development is similar to that of other 

 Lobatse, the larva passing through a Mertensia stage. 



