new “Worm” from Lower Ludlow Beds. 131 
It is, however, to be noted that, whereas the Ordovician 
and Silurian species of Protoscolew are associated with marine 
organisms in deposits of admittedly marine origin, Proto- 
scolew carbonarius is associated with various arachnids, insects, 
and a millepede, in a deposit of presumably fresh-water, or 
possibly brackish-water, origin. 
Beddard (1895, Monogr. Oligocheeta,-p. 9) says of Pro- 
natdites that “it is not by any means convincingly an 
Oligocheet.” At the same time he brings forward no counter- 
arguments, except in so far as he seems to suggest that, if it 
were, then it would support the view that Oligocheta were 
derived from the Polychaeta by way of such forms as the 
Tubificida—a view with which he disagrees. Beddard’s 
argument in the paragraph quoted depends on the distribution 
of the setee, but he can have known nothing about the sete 
of P. carbonarius, and must therefore have connected it with 
the 'Tubificide simply on account of its habitat. If, how- 
ever, the papilla of other species of Protoscolewx justify the 
conclusion that the sete were arranged as in Perichetide, 
then the question assumes a totally different aspect. 
Beddard’s own view is that the pericheetous arrangement 
of set is the primitive one, and for this view Protoscolea does 
seem to furnish that paleontological evidence the absence of 
which he deplored. So far as the known structure of Proto- 
scolex permits of a decision, there is no reason why the genus 
should not be referred to the Pericheetidee. It might, how- 
ever, be too hazardous an inference to suppose that this family 
of recent earthworms had true representatives in the Ordo- 
vician sea, and it is more probable that Protoscoler was 
nearer to the hypothetical Archichetopod from which the 
Phreoryctidee, Moniligastridee, Knchytreide, and Perichee- 
tide originated. It is already a good way removed from 
anything that could be called an Archannelid. 
Fortunately it has been possible to submit this instructive 
specimen of Protoscolex latus to Dr. Beddard and to Professor 
Seitaro Goto of Tokyo, and each has independently expressed 
the opinion that it closely resembles a modern perichetid., 
The preceding speculations have therefore the sanction of 
good authority. At the same time they are speculations ; 
other interpretations are possible, and it may be safest to 
summarize only the certain facts in the following 
Revised Diagnosis of Protoscolex. 
A worm-like marine organisin robably cylindrical, 
; 8 Veale Sy 
tapering rapidly at each end ; length from about 25 mim. to 
150 mm.; width in the compressed fossil from 0°5 to 3 mm, 
gx 
