ON AMPHIPORUS SPECTABILIS. 289 
1. He avers the inter-fascicular substance of the muscles 
had been undervalued, yet nothing of importance is men- 
tioned by him on the subject, and less figured, and unfortu- 
nately he does not discriminate the muscularity of many of 
the bands he alludes to. The radiating and other muscles 
and bands perform important functions in the Nemerteans, 
passing often in a most complex manner through the layers 
of the body-wall to the basis-layer, as well as traversing the 
body-cavity. 
2. He is doubtful concerning the internal circular mus- 
cular coat and the external investment of the proboscis. A 
single accurate longitudinal section of a suitable example 
would remove every trace of doubt. It is a very simple 
arrangement. A similar slip was made in regard to the 
reticulated layer, which he has now corrected, without, how- 
ever, indicating how this change occurred. 
3. His results under the head of Nervous System are two, 
viz., the incorporation of the cephalic sacs with the ganglia 
in the ANOPLA, and the assertion that the investment of the 
lateral nerve-trunks in the same group is composed of 
*“ hemoglobinous nerve-cells.” His notion that the cephalic 
sacs are a special respiratory apparatus for furnishing the 
“cephalic hemoglobin with oxygen,” is, I fear, somewhat 
visionary. He has the credit of clearly describing the cells 
in the investment of the lateral nerve-trunks. 
While on these points he is prominent, he has not ob- 
served, in his own form, the two very distinct thin layers inside 
the circular muscular coat of the body-wall, the important 
apertures in the proboscidian sheath, the generative tubes, 
and the somewhat pennate arrangement of the muscular 
fasciculi; the passage of the muscular fibres though the 
investment of the nerve-trunks (his ‘ hzemoglobinous 
nerve-cells”) in the Lineide, and he is unaware of the great 
modifications in structure in the Carinellide and Cephalotri- 
chide. 
Some very interesting observations on a land-Nemertean 
from the Bermudas by Dr. Willemoes-Suhm,! one of the 
naturalists on board the “ Challenger,” call for a few re- 
marks. This form (Tetrastemma agricola, Willemoes-Suhm) 
appears to be a typical member of the ENopa, and its struc- 
ture, on the whole, is fairly represented, under the great diffi- 
culties which a travelling naturalist must labour in investi- 
gating an organism so soft and so complex. ‘The absence of 
the cephalic sacsis peculiar and exceptional, and I should 
have expected them in such a form. ‘The mouth probably 
opens in front of the ganglia, not behind them, the former 
' * Ann, Nat. Hist.,’ June, 1874, vol. xiii, 4th ser., p. 409, Pl. XVII, 
