SALl'A. 18 



in the anterior pair, and with the h?ft anterior one by means of 

 the two small dors;il spurs of tlic hitter, and so on, for each suc- 

 ceeding pair, so that every indivi(hial of the chain is always con- 

 nected by spurs to the three innucdiatcly surrounding it in front, 

 on the side, and behind. 



As far as I have noticed, the chiiins remain connected till they 

 are fully grown, although the breaking up of the chain from any 

 cause does not prevent the components from living for a short 

 time, yet the chain, as a whole, is by far more active than the sep- 

 arate components when free. The largest chains 1 ha\e seen ai'c 

 somewhat over a foot in length ; in these the individuals meas- 

 ured about five eighths of an inch in length. This is much smaller 

 than the solitary forms, which attain a length of an inch. Sars 

 and Krohn were the first to repeat the observations of Chamisso 

 concerning the connection of the solitary and aggregate forms, and 

 they have clearly shown that the solitary form is asexual, al- 

 ways producing l)y budding a chain of Sa/pcs which are the sex- 

 ual forms, and bring forth but a single embryo developed from an 

 egg, giving rise to the solitary form. Huxley, Leuckart, and Yogt 

 have also since shown the entire accuracy of the observations of 

 Chamisso, and have greatly increased our knowledge of the organ- 

 ization and development of these animals. The ol)servations I 

 have made concerning the early development of the chain and the 

 solitary embryo are too fragmentary for ])ul)lication, and I am in- 

 duced to give this description of our >S((/j)a, in hopes of calling at- 

 tention to its existence on our coasts, and inducing those who are 

 more favorably situated than I am to develop further this intiM-est- 

 ing subject. 1 would also add that this Salpa is not the only free 

 Tunicate frequenting our coasts ; two s})ecies of Appetidicnldria 

 are extremely common, which have thus far escaped the attention 

 of zoologists ; they are closely allied to A. fiircata and ^4. loiigi- 

 cauda; they both occur in ^lassachusetts Bay and Long Island 

 Sound, while the Salpa Caboti has not as yet been found farther 

 north than Nantucket. 



Explanation of P"'KirKKs and Lettehinc;.* 



a. Anterior opening. c.f. Ciliated fossa. 



b, rosterior opening. c. b. Ciliated hand. 



e. Endostyle. '■/'. Small Salpa chain within form. 



n.ij. Xervons ganglion. </. Gill. 



* These Figures of SaJpa have a double numbering, one rcferriii;; to the figures in thi.s 

 work, the other beinir the same as in the 1jo-;:o:i Proc.'eilings. 



