272 ORTMANN—CORRELATION OF SHAPE AND 
Group OF FUSCONAIA SUBROTUNDA IN THE UPPER OHIO SYSTEM. 
The following is the taxonomy of this group here accepted. 
1. FUSCONAIA SUBROTUNDA (Lea).—Dia. 50 per cent. of length 
and over. 
Unio subrotundus Lea. ’31 (Ohio)—Quadrula subrotunda Simp- 
son, ’14, p. 892.° 
Dia. (Lea): 60 per cent. Simpson gives: 44, 49, 51 per cent., 
but only the last one would belong here according to the definition 
accepted above. 
Unoi politus Say, ’34—Synonym to subrotunda according to 
Simpson. 
Dia. (Conrad; 37): 53 per cent. 
Fusconaia leucogona (pars) Ortmann, Nautil. 27, 713, p. 89 (Elk 
River, W. Va.). 
2. FUSCONAIA SUBROTUNDA KIRTLANDIANA (Lea).—Dia. less 
than 50 per cent. 
Unio kirtlandianus Lea, 34 (Mahoning R., Ohio) —Quadrula kirt- 
landiana Simpson, 714, p. 891. 
Dia. (Lea) : 44 per cent.; (Simpson) : 33, 38 per cent. 
Fusconaia leucogona (pars) Ortmann, 1. ¢. 
Measurements taken from My Material. 
Loc. No. Max. Min. Av. 
Ohio River. 
POTESIMOTIMY cia.c ee clscraseicss see ete 5 67 51 50 subrot. 
IRortland parecer a meciore<ceieins snaier 4 52 49 5I subrot. (kirtl.) 
Rarkensburey | baecei cecislcmme see I 5I 51 SI subrot. 
S top MiaieyS) oe ie ucten wickets ticcimisieee 8 62 50 54 subrot. 
TOROMEO Mesa e csc cece oe leew isa stercionte 2 52 50 SI subrot. 
Cooks Hetrry.* 2.0. cee. cece eens 2 54 52 53 subrot. 
Tindtisthy -otetomecciec ers Oe eotereeeiiae 9 57 42 47 kirtl. (subrot.) 
Gormopoliste ree scrks tector ce 8 53 42 48 kirtl. (subrot.) 
9Simpson, C. T. A descriptive Catalogue of the Naiades, or Pearly 
Fresh-water Mussels. Detroit, 1914. All other references given without de- 
til may be found in this work. 
10 The first column gives the locality; the second the number of specimens 
at hand; the third, fourth and fifth, the maximum, minimum, and average of 
the percentage of the diameter; and in the last column, the name of the 
variety represented is given. When several forms are present, the first name 
is that of the prevailing (average) form, the other (in parenthesis) that of 
the less abundant one. 
