Morse.] 330 [March 19, 
Tt seems then reasonable to believe that some sort of relation exists 
between this marked feature of the Brachiopod test, and similar 
features in the worms and Crustacea. In the Brachiopods these 
tubules may have undergone some functional change, but until other- 
wise proved, they must be regarded as a distinct vermian character. 
In a large sipunculoid worm from Panama, kindly loaned me by 
Prof. Verrill, the inner lining membrane sends minute cecal pro- 
cesses into the integument, which is much thickened. There is 
possibly here some relationship. 
We also find in the Annelida mucous pores. This character 
must be common to all those animals secreting mucus from the 
surface, whether Mollusk, or Annelid; and as the peduncle of Lingula 
is glairy with mucus, we should naturally expect to find them 
present. This I easily succeeded in doing in living Lingule, using a 
4 inch objective of Powell and Leland. They were very minute, 
and closely crowded together. Their presence has never before been 
observed. The test of Lingula was also very glairy, but whether the 
mucus, which appeared to cover it, was exuded from the test, I 
could not determine. 
Sete. 
Fig. 9. 
In Mollusks, locomotion is effected 
mainly by a special organ, the creeping 
disk or “foot.” There is never secreted 
hairs, spines or sete. 
In the embryo of some Lamellibranchiates, 
there is said to occur two or three little spines, 
which are arranged along the ventral median 
line. 
In some species of Chitons, tufts of stiff 
spines issuing from the girdle have long been 
known. 
Whether these spines are homologically re- 
lated to the sete of worms, remains to be 
seen. From a cursory examination of them, 
Chiton spiculosus Gray. they appear to be modifications of the minute 
A. side view of Chiton, mag- pavement-like granules that occur in the gir- 
nified. B. side view of one . 
tuft of bristles in the girdle, ‘le of many Chitons. 
C. a tuft of bristles largely In Chiton spiculosus Gray, (alcoholic) from 
magnified. a. line of girdle. : ; 
fa, SGD aut CECE. Gaudaloupe, kindly loaned me for examina- 
B 
