262 Miscellaneous. 
Dinameba, and so closely clasped it as to contract the gelatinous 
envelope of the alga to little more than the thickness of the green 
cells. After some time the alga suddenly broke, and the two por- 
tions were gradually bent backward and made slowly to approach, 
so as to become parallel with each other. One of the pieces was 
then drawn within the animal a convenient length, broken off, and 
completely swallowed, and this was followed by a similar move- 
ment of the other piece. Shortly after the first rupture of the 
alga, when the two portions projected at an obtuse angle from the 
back portion of the Dinamaba, the animal contracted in length, 
and discharged from the right side a mass of bodies, which con- 
sisted of the separated cells of Bambusina, probably from the fila- 
ment it had swallowed in the afternoon. 
Prof. Leidy remarked that the two successive observations on 
the feeding of Dinameba appeared to be particularly fortunate, 
as they apparently explained certain facts in the habits of the 
animal. Dinameba had been noticed to be especially fond of the 
alga Didymoprium ; for it was found to be present as the principal 
element of the food in numerous specimens. Bambusina was less 
frequently found among the food contents of the animal. The 
alge were equally abundant in the localities of the Dinameba ; 
and, from the observations detailed, it would appear that the Drdy- 
moprium is preferred as food from the comparative ease with which 
its filaments are broken into pieces of convenient size for swal- 
lowing. 
The observations are, moreover, interesting from their indicating 
discrimination and purpose in the movements of one of the simplest 
forms of animal life. The movements are to be viewed as reflex 
in character, though resembling the voluntary movements by which 
the most intelligent animal would prepare morsels of food of con- 
venient form to take into the mouth. Im striking contrast were 
the movements, noticed on several occasions, by which an Oseilla- 
toria obtained entrance into the empty shell of an Arcella, and 
there, coiled up, crept round and round incessantly.—Proc. Acad. 
Nat. Sci. Philad., Oct. 1877. 
On the Structure of Amphioxus lanceolatus. By Prof. ScunnrpEr. 
The longitudinal muscles of the body-wall may be divided into 
the longus dorsi and rectus abdominis. The rectus reaches from 
the third segment to the anus, and lies beneath the chorda and 
within the longus dorsi. Its segments are the same as those of the 
longus; so that for the above extent each myocomma divides into a 
portion belonging to the /ongus and a portion belonging to the rectus. 
The laminze of which, as Grenacher demonstrated, the fibrillar sub- 
stance of the longitudinal muscles consists, converge in the longus 
towards the spinal cord ; in the rectus towards a point situated out- 
side the body—to the right for the right side, to the left for the left 
side. 
The nervous system may be very beautifully isolated by the 
method described by Owsianikow, but only partially ; and, indeed, 
Owsianikow’s figure by no means shows the whole nervous system, 
