TI4 The American Geologist. February, 1903. 
Discinisca stella of Nagasaki, Japan, "clung so closely to 
the rock, when first observed, that not until it erected itself 
on its peduncle did I become aware that it was a species of 
Discinisca. When I first dredged this species I mistook it for 
a species of Crania" (p. 323). 
Individual Age. — Regarding the age of individual Glot- 
tidia, Morse thinks that they live but one year dying in the 
autumn, and the same seems to be true of Lingula lepidula, 
but L. anatina may perdure for two or more years. 
Protegulum. — In Lingula lepidula "the [dorsal] protegulum 
is oblong-ovate, the posterior margin being straight; the per- 
iphery of this stage is distinctly yellowish in color, and this 
is of interest as marking a distinct period in the shell growth" 
(p. 322). 
"In Glottidia pyrofinidata, the protegulum, while showing 
a straiglit posterior margin with a slight shoulder as it con- 
nects with the subsequent growth, is circular in outline. * '^ * 
In a species of Lingula collected in Nagasaki the protegulum 
is ovate with the same straight posterior margin. In all these 
instances, the peduncle is firmly adherent to the ventral shell, 
the beak of the dorsal shell standing free with an interspace 
between it and the peduncle." 
"In Discinisca lamellosa, the [dorsal] protegulum is elong- 
ate-ovate with anterior and posterior margins equally rounded. 
A perfectly circular nucleus is outlined in the posterior half 
of this stage. * * * * It is an interesting fact that the succes- 
sive stages of Discinisca begin with a nucleus eccentrically 
related to a perfectly circular stage ; this circular stage, in 
turn, being eccentrically related to an oblong-ovate stage, 
which is the true protegulum ; and this, in turn, being eccen- 
trically related to an adult stage which is finally orbicular 
again." 
The phylogenetic significance of Morse's remarks on the 
protegulum of Discinisca is not yet ascertainable, and this is 
particularly true in the light of the recent work on Lingula by 
Yatsu.* Until this year it has been thought that all brachio- 
pods developed the first shell, or protegulum, on the inner side 
of the mantle before it is reflexed forward over the anterior 
* On the development of Lirgula anatina. By Naohide Yastu. Journal 
College of Science Imp. Univ. Tokyo, Japan, xvii, pt. 2, art. 4, 1902, pp. 1-112, 
pis. 1-8. 
