Folliculinids of Ago Bay, Japan — M atthews 
237 
50 H 
Fig. 5. Diafolliculina rotunda. 
A, Ventral view of anterior portion of lorica show- 
ing ; a, collectoderm ; b, neck opening ; c, ventral valve ; 
d, dorsal valve. 
B, Lateral view of anterior portion of lorica (right 
side) showing: e, neck; j, ventral valve; g, dorsal 
valve. 
many closely related species which appear to- 
gether in great abundance . 3 
3 Silen (1947:47) stresses that species can only be 
determined by a study of abundant living material and 
Hadzi (1951:37) says, "We have, however, in prac- 
tice, often only a few empty lorica and preserved in- 
The lorica (Fig. 6e ) is approximately 500p 
long of which perhaps half could be considered 
neck. Because no valves separate sac from neck, 
only 4 or 5 very indistinct spiral whorls (<7) in- 
dicate where one leaves off and the other begins. 
The lorica therefore tapers only gradually 
from a rounded, attached, proximal end (g) 
to a morning-glory shaped distal end. The wide, 
delicate flare ( a ) is strongly marked by light 
and dark longitudinal stripes ( b ) which become 
indistinct posteriorly. No neck extensions are 
present. The width of the sac is 150p, its 
height, lOOp. 
The peristomal lobes (c) are long, even, and 
terminate bluntly without finger-like projections. 
The nucleus (/) is spherical, measuring up to 
38p in diameter. The foot (h) is non-spatulate. 
The color, characteristic of members of this 
genus, is a deep blue-green. In reflected light 
the animal is bright red. 
Lagotia expansa var. depressa Hadzi, 1951:78. 
La gotta expansa var. depressa was first taken 
at Tatokushima, June 19, 1965 on shells of the 
large Japanese oyster Pinna attenuata. More 
precisely, it was commonly found between the 
sacs and actually in the necks of Lagotia gignn- 
tia. Figure 1A shows L. expansa depressa ( b ) 
on the calcareous shell of Spirorbis sp. and on 
the operculum ( a ) of the living animal. To my 
knowledge, this is the first time that a folli- 
culinid has been reported attached to a moving 
part of a serpullid. Figure IB is a ventral view 
and 1C, a ventro-lateral view. Both show the 
flattened lorica (J) with smoothly rounded 
proximal ends and typical longitudinal stripes 
( b ) on short, distally flaring necks ( a ). The 
length, breadth, and height of the lorica fall 
well within the limits of those given by Hadzi 
( 1951 : 81 ). 
The peristomal lobes ( c ) are of even length 
and end bluntly without finger-like projections. 
dividuals to work with. It is then not remarkable 
that today we still have not distinguished sharply all 
species and are unable to name them uniformly.” The 
problem is probably even more complex. Recent ob- 
servations on the dimorphism of the macronucleus 
(Uhlig, 1963:115-121, fig. 3 a and b) place in serious 
doubt the validity of certain taxonomic characters 
used to distinguish folliculinid genera. However, until 
the reliability of characters is studied in many genera, 
these species are assigned to the genus Lagotia. 
