494 PROCEEDINGS OF SCIENTIFIC SOCIETIES. 
'The perivisceral wall is made up of two layers of muscular fibres which 
cross each other, giving it a reticulated appearance. While the young 
shell is oval in shape there is marked out a perfectly circular area, indi- 
cating that at the outset the embryo possesses a circular plate above and 
below. The muscles were very large and occupied most of the perivis- 
ceral cavity. The sets fringing the mantle were very long, those from 
the anterior margin being nearly three times the length of the shell. The 
mantle margin, the blood lacuns, and the bands of muscles to move the 
with the cavity of the peduncle. The circulation was voluminous an 
rapid; no trace of pulsation could be detected. The fluid was not blood 
proper, but chyle-aqueous, cate distinct from this was the proper heart and 
blood as bic out by Hancock 
From repeated sca tenis of the hiro crs he could state itum 
regarding the nature of these organs. 'The internal mouth was plaited 
and turned towards the sides, the remaining partion of the heti was 
reddish in color, and glandular, eh dbo A performed a renal function 
as in similar organs among the 
The sexes were sepa icto. ie estis: arms had a limited power of mo- 
tion. The coils could be raised or depressed, and the axis of the coil could 
be at boom angles to the longitudinal axis of the body or parallel to it. 
ontents of the stomach were found in all the lobules of the liver, 
nating that the food circulated in these hepatic prolongations, as in 
t nelids. Upon young Lingula a perfectly circular area could be seen 
near hé beak of the shell; this indicated the form of the embryo shell 
the specimens he had brought from North Cavell in May were alive at 
this date, August 19th. They had been confined in a small cid ees a 
little sand, and the water changed every two or three days. This i 
was Bees tbs since Lingula had existed from the earliest pend 
ages to the present time. 
In describing pode he mentioned in detail, the muscular, alimentary, 
he rt 
Hancock were traced to a ganglionic enlargement in the divaricator 
muscles, and were unquestionably nerves as pointed out by Owen. 
