1878.] 343 [Morse. 
Sabella, Fig. 18, to show the similarity of the cephalic arms in the 
two. In one the portions are concentrated, while in the other they 
are drawn out. ‘ 
Dr. E. Ray Lankester,! in an exceedingly interesting sketch of Teredratula 
vitrea, compares its arms and cirri, to the gills of a Lamellibranchiate. In 
this comparison he is certainly wrong, for the gills of the Lamellibranch de- 
velop upon the sides, and in Spherium and other genera, towards the posterior 
end; while the cirri, with the arms sustaining them in the Brachiopods, are 
strictly cephalic. Had he compared the arms of the Brachiopod with the mem- 
branous palpi of the Lamellibranch, he would have come nearer the true aftin- 
ities, for these form folds above and below the mouth, are united partially on 
their inner margins as I have observed in Unio and other genera, and in some 
species are very long. 
Renal Organs. 
Claparede has noticed that in the segmental organs of many worms 
a portion of the tube is glandular, and he has reason to suppose that 
the glandular portion represents the renal organ. Whether Clapa- 
rede is right in his conjectures or not, it is interesting to recall the 
fact that years previous to this statement, Huxley suggested that the 
glandular portion so very conspicuous in the oviducts of Brachiopods 
was of a renal nature. 
The slightest examination of the oviducts of Brachiopoda shows 
the tubular portion not only glandular, but colored, as in the oviducts 
of worms. This portion is also intimately connected with the vascu- 
lar system, and whether renal in its nature or not, the closest similar- 
ity exists between these portions and similar parts in the segmental 
organs of Annelids. 
Nervous System. 
The general plan of the nerve system in the Vermes appears to be 
that of a nerve collar surrounding the cesophagus, sending off a ven- 
tral cord in a median line of the body.. In the lowest worms there 
seems to be simple cephalic gancelia without the ventral cord. In 
Sipunculoid worms a single cord running along the ventral portion of 
the body sends off delicate threads at right angles to it. In the 
higher worms the ventral cord is longitudinally divided into two 
symmetrical halves. In some worms there appears only a slight space 
1 Annals and Mag. of Nat. Hist. Vol. xr, Fourth Series, No. 62, p. 93. 
2 Hancock, ibid., p. 822. 
