2 
C. ensis, Delp.— Occasionally in Minnesota, Pennsylvania and 
New Jersey ponds. ' 
C. prelongum (Breb.) Delp.— Luzerne Co., Penn., and Min- 
nesota. 
C. Brebissonii, Delp.— Similar in form to C. prelongum, but not 
striate or recurved at the ends. 
Minnesota. 
C. subcostatum, Nord.— Florida Ponds. 
C Delpontii, Krebs.— Delponte called this C. crassum, a name 
already applied to a species described by Rabenhorst: it was there- 
tore changed as here given. 
Frequent in Luzerne Co., Penn. 
C. /rt^/z.-m Breb.— Differs from" allied forms in its small size and 
proportionate length of body with the beak. 
I'lorida ponds. 
Docidium Archeri, Delp.-Luzerne Co., Penna. 
fr^ ;''^^^««> Delp.— According to Delponte this species is separated 
W?i fl ^^?"'^''"' by being always straight, never bent, without a 
Dasal inflation, stouter and longer. I have frequently met with it, 
but am not yet satisfied that it is different from D. Baculum. 
InnT^" .1. f" i^^^P-^ Wolle.-Cell cylindrical, six to ten times 
wf/ '^an broad; apices rounded, basal inflation of semi-cell large, 
h^=r^ ,^ ' ,^y^^oderm smooth. Diameter at ends, 50/^; inflated 
base 65/^; length about 600/^. 
Ocean Co., New Jersey. 
I .rWr'tT''""" ^'""-/'^'^^^^^ Delp. (Plate xlvii. Figs. 23 and 25.) 
time^^ ""t^^ ^^' ^ ^^™ ^'"^^^y distributed, but variable. Some- 
n?mlJr '^^T ^^^ ^- ^''ipiicatum in size and shape, but differs in the 
Sireefh, . ^""'"^"g^"^^"* of the granules, which are not in series of 
the nnnf i"„*^°'}t'""ous concentric rows. Sometimes they cover 
occnr^vvlH K °^ ^''' semi-cell, then again only one or tvvo rows 
usuallvn r' ^, near, the margin; the centre and basal half are 
De nnnf. K . J^^^^emi-cells are not so straight-sided as figured by 
recl'argLl'a 'oblong. '"^^ ^"' ^"^ ^'^^ -^ ^'->^^ -°- - '^^^ 
s name; it is 
Reinsch has called a very different form by thi 
riy If not entirely identical with C. cyduum, Lund. 
Venn'S %^''"'' ^^'^- ^^^gs. 26 and 27).-New Jersev and 
fm^n^r "J,^- ^^^^"^^bles C. orthostichum, Lund., but is somewhat 
smaller, ends truncate and granules not so regularly arranged. 
th^rT'.^vf ■■^'^"^i^\'^- '^- <^'g^- ^l and 34).— Small, one-third longer 
inan wide, end of semi-cell broadly truncate; sides convex, with 
siignt contraction near the end; side view circular with end truncate, 
membrane finely and closely granular. Diameter ^<,^l ; length 33M- 
Stillwater, Minnesota. 
C. circulare, Reinsch. (Fig. 37)— Toevi marshes, Florida. 
^.perforatum, Lund. (Fig. 32).— Near Minneapolis, Minn. 
hrn H ^^^^^'^",M. n. sp. (Figs. 18-20).— Cell one-half longer than 
uroaa; semi-cell gradually enlarged from a narrow base to the broadly 
xVht\ fl ' ^"^ ^'^'^ broadly elliptic; lateral view circular, with 
'iigbtiy flattened sides; membrane finely punctate or smooth. Di- 
ameter 25-28//; length about 40//. 
