Pa 
ogo : The American Naturalist. [March, 
wildly open. The starfish continues its attack, but as soon as one of 
the pedicellariæ touches an ambulacral tube it immediately bites it; we 
may suppose that the pain produced is considerable, for the arm of the 
starfish is actively withdrawn, but it always carries with it the offending 
pedicellaria fixed in the wound. 
In some cases the first bites are sufficient to drive off the starfish, but 
in others it prolongs the attack, and then it is very interesting to see 
the urchin unmask its pedicellariæ on the points attacked, and, so to 
speak, follow the movements of the enemy by showing its teeth. In a 
first fight the victory is always with the urchin, and the starfish retires - 
covered with wounds. But, as each pedicellaria serves only once for 
the defense of the urchin, it is gradually deprived of its organs for this 
purpose. If an urchin is put with several starfishes and abandoned to 
its fate it succumbs at last. 
The moment an Echinoid is warned by its peripheral nervous 
system of the danger which threatens it, it moves its spines in a way 
which has nothing in common with the ordinary movements of these 
organs, and which has no other object than to unmask its gemmiform 
pedicellariz. It is of interest to observe that this movement is exactly 
the opposite of that which is produced when the surface of the test is 
wounded by, for example, the point of a needle; in that case the 
spines and pedicellariz are inclined towards the wounded part. 
Hekaterobranchus is the name given by Miss F. Buchanan ? to a 
Spionid worm discovered at the mouth of the Thames; but in a post- 
script she thinks it may belong to Webster’s genus Streblospio. The 
characters are a single pair of dorsal branchiz situated on the first seg- 
ment; cephalic tentacles, not grooved but ciliated all over; prostom- 
ium well developed ; four eyes ; first segment prolonged below to form 
a collar; pharynx evertible and richly ciliated ; a single pair of thoracic 
nephridia, opening on second segment, reaching back to sixth segment, 
and thence bending forward again, 
The Anatomy of Scutigera.—Curt Herbst has discovered some 
interesting facts regarding this’ Myriapod. In his Dissertation’ he 
describes five systems of glands in the head where he only expected to 
find the salivary gland described by Dufone. The first is a pair of 
tubular glands opening at the base of the first maxille. The sec 
pair belong principally to the segment of the second maxilla and open — 
in a deep pit on the side of the head. The third system belongs tO the 
2? Quarterly Jour: Micros. Sci., XXXII., p. 175, 1890. 
3 Anatomi tersuct 4 
vittoria (TAT TOs PS 
g tigera Coleoptrata. Jena, 1890. 
