ASCIDIANS OF GUERNSEY. 



209 



Salpa democrataea-mucronata (?) . In tow nettings, sometimes plentiful 

 (Sinel). This is a very interesting animal, partly on account of its 

 life history and partly because of its great luminosity. These Salps are 

 found in two forms, hence they show ''alternation of generations." A 

 solitary form gives rise by internal budding to a tubular stem which 

 contains prolongations of all the principal organs of the body. This 

 stem becomes segmented into a series of buds, which are set free in 

 groups, when their development is sufficiently advanced. These sets of 

 animals represent the "chain" form in which these Salps are found. 

 The chains were formerly considered to be distinct species, hence the 

 double specific name of many. The members of the chain are sexual and 

 give rise to embryos which develop into simple Salps like their grand- 

 parents. 



Order III.— Larvacea (Herdman). 

 Family.— APPENDICULARID.dE (Bronn). 



Body more or less ovate, with the longer axis antero -posterior, and 

 having a large appendage (tail) attached to the ventral surface. Test 

 periodically developed into a very large investing capsule which is thrown 

 off from the body after a time. 



AppendiCUlarla flabellum (?).— In tow nettings, sometimes plentiful 

 (Sinel). There is no alternation of generations, and no metamorphosis 

 in its life history. 



