EXPLANATION OF PLATE XXXIIL 



FiGrPvE 246.— Cynthia partita, variety stellifera, (p. 701 5) natural size. 



247. — Cynthia carnea, (p. 701 ;) natural size. 



248. — The same, (p. 701:) younger specimens, natural size. 



249. — Eugyra pilularis, (p. 700 ;) natural size. 



250. — Molgula Manhattensis, (p. 699 ;) smooth variety, natural size. 



251.— Molgula arenata, (p. 699 ;) natural size. 



252. — Botryllus Goulclii, (p. 702;) colcuy incrusting the stem of Tuhularia, 

 somewhat enlarged. 



253. — The same; one of the zcoicls, enlarged ten diameters ; a, anal tube and 

 orifice ; s, stomach ; g, groove and vessels along the edge of the branch- 

 ial sac, inside ; 0, left ovary ; &, bud, attached by a slender stolon. 



254. — Salpa Cabotti, (p. 706 ;) solitary individual, from the dorsal side, enlarged ; 

 7*, heart ; s, small chain of salpas budding within the old one. 



255. — The same; one of the individuals from a mature chain, three-quarter 

 view enlarged; a, posterior or anal opening; &, anterior or branchial 

 opening; c, processes by which the individuals of the chain were 

 united; /<, heart; w, nervous ganglion ; 0, nucleus ; r, gill. 



256.-- -Escharella variabilis, (p. 713 ;) few of the cells, much enlarged. 



(Eignre 256 was drawn by A, Hyatt; 254 and 255 were copied from A. :Agastiz ; tlie others were 

 drawn by A. E. Verrill.) 



