y^ 



••xc,. 



reVERTEBllATA OF MASSACHUSETTS 



Class TUNICATA. 



* 



Acephalous Mollusks with a soft, organized, coriaceous or gelat- 

 inous shell or test provided with a branchial and an anal orifice. 

 Mantle forming an interior coat. Gills attached wholly or partly 

 to the internal surface of the mantle. Mouth without labial tenta- 

 cles, placed below the gills. Animals single or aggregate, fixed or 

 free, hermaphrodite, undergoing a metamorphosis in their young 

 state. 



The Tunicaries are entirely marine, and are very numerous in all 

 parts of the world ; adhering to rocks and sea-weed, their strange, 

 bag-shaped, leatliery bodies may be seen along the strand at low- 

 water, ejecting, when touched, the sea-water to some distance ; and 

 on the ocean their lengthened sinuous chains, or pellucid phospho- 

 rescent tubes, cannot fail to arrest the eye of the voyager. The com- 

 pound forms exhibit, in the varied arrangement of the individuals 



* Finding nothing in Dr. Gould's manuscript relating to the Ascidians, and being my- 

 self unacquainted with the class, I could but collate the few published descriptions of spe- 

 cies, and obtain what drawings had been made by those who have collected the animals. 

 Through the kindness of Professor Agassiz, the rich treasures of the Museum of Compara- 

 tive Zoology have been laid open to me, furnishing many figures beautifully drawn from 

 nature b}' Mr. Burkhardt. Dr. Packard has also given the use of the species collected by 

 him, from which Mr. Morse has drawn Plate XXIII. as correctly as is possible from speci- 

 mens long preserved in alcohol. 



To Mr. Alexander Agassiz I am indebted also for the use of the woodcuts of Salpa. 



The descriptions of families, genera, &c., are copied from " Tiie Genera of Recent Mol- 

 lusca." I have included all species actually described as having been found from New 

 York to Labrador. A reference to the " Bibliography of North American Conchology " 

 will show that species have been mentioned by name as inhabiting New England which 

 are not included in the following pages. They are not accompanied by descriptions. 



W. G. B. 

 1 



