NOTES ON A SPECIES OF BARNACLE. 
411 
In two or three crabs having- a large number of barnacles of all sizes, minute 
white specks on the gills, when examined with a lens, proved to be attached cypris or 
stages between the attached cypris and the typical lepadide form. 
Fig. 14 is a sketch made from an attached cypris that had been mounted in 
balsam; the gill had been torn from the adhering antennas (ant.). The valves of 
the very convex and bilaterally compressed shell are continuous dorsal ly (.$•/*.); their 
ventral edges are connected by the adductor muscle (ms. ad.) and are apposed except 
where the adhering antennae are protruded in front, and posteriorly where the 
branchial opening, through which the thoracic feet (th. 1. /, 17) are protruded, 
admits the passage of water into and out of the branchial chamber. The shell is lined 
by the mantle (ml.)- anteriorly, between the mantle and the shell is seen a thick layer 
of loose tissue (y), which is perhaps a thickening of the mantle, or possibly is due to 
imperfect preservation; while it is not figured by Hoek or Claus (in Korsheldt & 
Heider) it is in all of my specimens. The dorsal infolding (inv. d.), separating the 
part that is to be the capitulum from the portion from which the peduncle is derived, 
Pig. 14. — Attached cypris. Optical section, with some projections xlfi3. (Drawing from mounted specimen.) 
is well developed. Just anterior to this is the ventral invagination (inv. v.), causing 
the peduncular portion to be bent upon itself. In this infold are the large paired 
eyes (p. e.) left behind by the withdrawal of the stalk integument, but still attached 
to the cuticle, and later to be thrown off (Korsheldt & Heider ’99, p. 218). The 
unpaired nauplius eye (u. e.) is seen near the ventral end of the dorsal invagination, 
instead of anterior to the caeca as in Lepas (Claus’s figure of the cypris of Lepas 
pectinata in K. & II. ’99, p. 210). The mouth sit, the top of the “oral cone” leads 
by the oesophagus (ces.) into the enlarged stomach (st.) from which the intestine (int.) 
proceeds. Opening into the oesophagus are a pair of caeca, cc, (Iloek); in Claus’s 
figure a similarly placed cavity is called the liver. Ventral to the alimentary canal 
is seen the chain of thoracic ganglia (g. /to g. VI) without commissures; the first is 
much the largest. Just above the oesophagus from this one is the supracesophageal 
ganglion (g. s.). 
Specimens in all stages of the metamorphosis from the attached cypris to the 
perfect lepadide adult can be found on the crab gill. 
*i- 
int. 
