D. BRYCE ON THE MACROTRACHELOUS CALLIDIN^. 21 



ticular heed, and I can predict that he will be astonished at the 

 well-marked individualities which he will find to exist. 



Commencing with the trochal discs, he should note their 

 breadth, relative distance, height from secondary wreath, and 

 ^iroportion to breadth of head ; the positions in swimming, feed- 

 ing, crawling, partial retraction, and complete retraction ; the 

 shape of the rami, and the number of teeth on each, taking care 

 that he does not mistake fine teeth for the fine striae frequently 

 present ; the structure of the frontal column and the membran- 

 ous shielding flap with which the tip is provided, and which 

 might be mistaken for two hooks ; the antenna, its length and 

 direction ; the skin, its folds, surface, and pseudo-armature. 

 The foot should be considered as including only the post-anal 

 segments. The spurs, though usually short, are very distinctive, 

 and the toes very difficult to see at all, far less define and count. 

 The treatment of the food and the various movements assist- 

 ing the digestive action should be watched while the animal is 

 feeding. Above all, sketches should be made and copious notes 

 taken at every opportunity. 



Before mentioning the characters of the four new species I 

 wish to say that I have not been able to identify, to my own 

 satisfaction, any of the Gallidince described by Mr. Gosse, and 

 that if anyone here can furnish me either with specimens or 

 with further particulars of these species he will confer upon 

 me a very great favour. 



Gallidina plicata, n. sp. 



Sp. Ch. — Elongate and without medial swelling when crawl- 

 ing. Central portion of trunk with coarse dorsal and lateral 

 skinfolds, mostly extending forward over anterior portion and 

 the central dorsal pair extending over posterior segment, the 

 latter, conspicuously swollen and hood-like, constricted at upper 

 and near lower end. Foot only displayed when crawling. 

 Spurs moderately stout and short cones, with slightly produced 

 points, showing (rarely) narroAv interstice when at greatest 

 separation. Wheels rather large ; mastax ample, rondo ovate, 

 two teeth on each ramus. 



Intestinal action a periodic heaving, food not moulded into 

 pellets. 



It is possible that the hood-like segment, apparently consist- 



