AND EMBRYONIC FORMS. 419 



opt";'!' whi '; e T d °T n ! '" d ' He3 " y ' Wnged ***** M °" «- >»»4W 

 opening, which terminate, in a more or less enlarged, flattened process, which has 



somewhat long papilla. On the upper exterior part of this fleshy border there" 

 ate and «*«/„.„. iWM opm^ large, with rather large papilla, Ami 



rz r t er sm ;"' with : hick ' spoited edses > ^ ■•*«*" «" 



below Coll r7 TT ' Sligh " y °° l0red °" thC in " el ' «"«" »» d »»««» 



oeiow. Color of the mass whitish. 



Ern^ucskell ovately-pouch-shape, white, has no hooks. See Joun, Acad. Nat. 

 Sci. (2), vol. iv. pi. 5, %. 13, and Obs. vol. vi. p. 47 



Columbus, Ohio, H. Moores; and Fox River, Illinois, H. C. Grosvenor. 

 Unio zkzs, Lea, Trans. Auier. Phil. Soc, vol. iii. (2)) pI . llf fig . u> aud ^ ^ . p ^ 



A single male specimen only received. 



of ^7^ l^ "^ f D ' inner ° ne mUCh the ^ free nearl ^ the whole length 

 of abdominal sack. Palpi small, very thin, subjugular, united only for a short 

 distance on the posterior edges. Mantle very thin, colored on the margin only abo 



aZ 4 T mngS - Br TT ^^ rath6r ""*> WHh ™V — o J snl 

 We Itf 7 ^7 ' bkckish ' With ™7 small papilla ^ am ; opmmg 

 laige, spotted within and united below. Color of the mass white 

 Columbus, Ohio, H. Moores. 



Cam Nov.- E .„. i0I , U , T ra „». A.„. Phi,, So„„ ,,,, „,. vi . pl . 24 , , g . n4 . 0bs „, .. p m 



tatalri"' " k ' m """I'' 8 " early " le Wh °' e le " Sth ° f 0Ute '' *«**>. M«*i* »" 

 1, inferior margin, each sack terminating with a whitish spot. Br^ice large, 



fun, inner ones much the larger, some free only a short distance on the posterio 



portion of abdominal sack and some not feee. Mpi small, thin, subjugular, t- 



ached but a short distance on the posterior edge, Mantk very thin, thiekene a, 



the margin and fringed below the branchial opening. BranchM ^ ra ther large 



211%™™™: Sraa " Papilte - A ' Ul *** SmalI > Wackish, with minute 

 papilte %«Mi op*,*,, l 0n& spotted within alld uuited Mqw 



mass whitish. 



•»»-*> *« pouch-shape, clear white, has no hooks. See Jouru. Acafl. Nat. 

 bci., (2,) vol. iv. pl. 5, flg. 14, and Obs. vol. vi. p. 47. 

 Fox River, Illinois, H. C. Grosvenor. 



iWfo. Six females which were examined had from fifteen to twenty rather 



arge ovists in each of the outer branchi*. It is remarkable that the braiml i « in 



wo .specimens should be united the whofe length of the abdominal sack wl ie 



others should be open f„ r . 6 b„ rt distance , showi „ g ^ ^ ^ ^ ^ * 



