EXPLANATION OF PLATE XXXII. 
FIGURE 246.—Cynthia partita, variety stellifera, (p. 701;) natural size. 
247.—Cyuthia 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 Gouldii, (p. 702;) colony incrusting the stem of Tubularia, 
somewhat enlarged. 
253.—The same; one of the zodids, enlarged ten diameters; a, anal tube and ori- 
fice; s, somach ; g, groove and vessels along the edge of the branchial 
sac, inside; 0, left ovary: b, bud, attached by a slender stolon. 
254.—Salpa Cabotti, (p. 706 ;) solitary individual, from the dorsal side, enlarged ; 
h, heart; s, small chain of salpe# 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; b, anterior or branchial 
opening; c, processes by which the individuals of the chain were 
united ; h, heart; n, nervous ganglion; 0, nucleus; 7, gill. 
256.—Escharella variabilis, (p. 713;) few of the cells, much enlarged. 
(Figure 256 was drawn by A. Hyatt; 254 and 255 were copied from A. Agassiz; the others were 
drawn by A. E. Verrill.) : 
