PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 280 



■ many ; h- =: few ; + == or more ; ^ = irregular. 



Plau of insertion plates. 



Regular, branching 

 do 



-do. 

 -do. 

 -do. 

 -do. 

 .do. 

 -do. 

 -do. 

 -do. 

 -do. 

 -do. 

 -ilo. 

 .do. 

 .do. 

 -do. 



(Lophyroidea.) 



Kegular, branching . . 



do 



do 



do 



Unflssured 



Regular 



(Aeantlioidea.) 

 Regular, branching . . 



-do. 

 .do. 

 .do. 

 -do. 



.do. 

 .do. 



V. all thrown forward. 



V. po.st. thrown forward. 

 do 



(ScMzoidca.) 



I Eeinilar, po.sterior valve C 

 ) slit between 2 ridges. ( 

 Str. forward, deep slit 



( Placiphoroidca.) 



Str. forward, Hut behind 



Regulur, Hat behind 



Regular, ribbed behind 



do 



do 



do 



(Mopaloidea.) 



\ Regular, jjostorior valve C 

 — S laminated. \ 



42 Thrown forward, laminated 



4:! ] do 



4;tt I Thrown forward somewhat- 



4:!& Thrown forward much 



45 

 ma 

 4r.6 

 47 



4S 



4S« 



4U 



Tail plate creuate behind. . . 



! (Cn/ptoidea.) 



Regular, behind variable. . . 



Mopaloid '. 



do 



Coarsely mopaloid 



I {Chitonclloidea.) 



Very sagittate 



..---■.do. 



Intermediate 



Slits in valve. 



9 



7-8 



2f 



1 



1 



2+ 



1 



1 



1 



2 + 



1 



2 + 



1 



1 



1 



1 



1 



1 



1 



2-1- 

 1 

 I 

 * 

 1 



1 



1 

 1-2 



0-1 

 

 1 



Teeth. 



Eaves. 



Sharp, normal , Projecting . 



Sharp, long, smooth..! Minute 



Shari), normal 



do 



Gills. 



...do 



..-.do 



...do 



...do 



...do 



...do 



Excurved, phimato. 



Eseuived. solid j Rrojectinp 



Rouiih, propped. .. | Short . 



Proiecting 



..-.do 



...do 



... do 



...do 



Projecting, long 



do 



....do 



.--.do 



Solid, not propped. ..[... do 



Solid, propped I .... do 



Sharp, curved Short, spongy . 



Blunt, serrate 



...do 



Sharper, serrate 



Siiaiper, serrate, loni 

 Ulunt, fimbriate ... - 



0) 



Blunt, grooved 



Longer, grooved 



.-..do 



...do 



. do 



Long, smooth ... 



Short, spongy . 



...do '.-'-. 



.--.do 



Very short 



Shoit 



(0 



m 



Projecting, 



grooved. 



do 



...do 



...do 



Very short 



Moderate, not 



giooved. 

 Moderate, spongy (?) 



(?) 



(?) 



Amb. 



Ami). 



Amb. 



Amb. 



Am b. 



Amb. 



Amb. 



Amb. 



Amb. 



(?) 



(?) 



(?) 



(?) 



Med. 



Amb. 

 Amb. 

 Amb. 

 Amb. 



(?) 

 (?) 



Amb. 



(?) 



Amb. 



(?) 

 (?) 



Propped, smooth 



Short, sharp, smooth.; Projecting. .. .. (?) 



Very long, sharp, i Short Amb. 



smooth. 1 

 Kormal, sharp, i Moderate (?) 



sniooth. 

 Very long, sharp, j Very short ! Amb. 



smooth. 



Blunt, mgose Moderate (?) 



Sharp, si'rrate I Long ; (?) 



Shall), long Small I Med. 



None behind 



Normal, serrate 



Slightly propped 



Exciirved 



Sharp 



Sharp, very long, 

 .smooth. 



L"ng, propped 



Mod., simple 



Very long, propped. . 



Long, sharp, smooth 



V(!rv long, sharp, 

 sniooth. 



Very long, sharp, ru- 

 gose. 



Crenate, sharp, 

 smooth. 



Deeply furrowed i (?) 



Moderate (?) 



Small I Amb. 



■■■■do I (?) 



Minute ' (?) 



...do ' (?) 



Minute Med. 



Small 



Minute, spongy.. 



SmtUl : . . . 



Minute 



Very long, smooth . 



....do 



...do 



....do 



....do 

 ....do 



Minute 



— do Med. 



, do Amb. 



I None ! Amb. 



(?) 



Amb.. 



Med. 



(?) 



(?) 

 Long. 



) V( ry short, except < [Distinct Post. 



5 at sutures ( • • do Post. 



Mod. lung in fiont. .. Minute I (?) 



Proc. Nat. Mus. 81^ 



-19 



Feb, 99, 1889. 



