EXPLANATION OF PLATE XXNXMUI. 
Figure 246.—Cynthia partita, vuriety stellifera, (p. 701;) 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. 
262.—Botryllus Gouldii, (p.702;) colony incrusting the stem of Tubularia, 
somewhat enlarged. 5 . 
253.—The same; one of the zodids, enlarged ten diameters; a, anal tube and ori- 
fice; 8, 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; u, posterior or anal opening; 0, anterior or branchial 
opening; ¢, processes by which the individuals of the chain were 
united ; h, heart; n, nervois ganglion; v, nucleus; 7, gill. 
256.—Nscharella variabilis, (p. 7133) tew 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) 
