DAVID BRYCE OX TWO NEW SPECIES OF PUILODINA. 525 



processes whose ^function, as I believe, is simply to act as mere 

 supports to the foot when the animal is feeding, and as buffers to 

 lessen the shock of the recoil when the animal, in alarm, con- 

 tracts itself violently upon its affixed foot-base. 



It has been stated that the spurs are perforate, but I have not 

 in any species been able to detect any trace of perforation, or of 

 capability, by the exudation of mucus or otherwise, to attach 

 the spurs, or to lay hold by them in any way of the surface they 

 may touch. Their bases are undoubtedly hollow, but their apices, 

 appear to me to be solid and imperforate. They are usually stiff^ 

 but may occasionally be observed to bend when under temporary 

 strain. 



When the foot is fully protruded, as in the specimen sketched,, 

 it is seen that the penultimate segment extends a little way 

 below the bases of the spurs. A few species which usually 

 feed while extended to their greatest length, habitually show 

 this lower portion of the segment. In species which adopt 

 a more or less squatting position when feeding, it is rarely 

 exposed. 



The terminal segment is furnished with two pairs of toes, tho 

 dorsal and the terminal. The dorsal toes are usually much 

 smaller than the terminal, and are placed at some distance above 

 them. When in their natural position they stand out from the 

 foot surface nearly parallel to each other (not strongly divergent, 

 as shown in sketch, and as caused by pressure of cover-glass). 

 Although it is clear, when the foot is thus protruded straight out 

 behind the body, that these two toes are on the dorsal side, this- 

 position is rarely seen when the animal is free, and does not occur 

 in the ordinary course of locomotion, but only when it desires 

 to creep backwards, as sometimes happens. In the act of 

 creeping forwards, when the body has been extended to its utmost, 

 and hold has been taken wath the tip of the rostrum or anterior 

 extremity, the foot is released and the t)ody, partly contracting 

 in telescopic fashion, partly arching like the caterpillar of a 

 geometer moth, is drawn up towards the rostrum. At the 

 moment when the foot has been brought forward as far as 

 possible and seems to be on the point of being set down, the 

 terminal segment, until now concealed, is shot forward below the 

 animal, the terminal toes are applied and become affixed, and 

 almost simultaneously, by the telescopic action of the foot parts, 



