274 THE ZOOLOGIST. 



paired. No dorsal pores. Intestine begins in xiii. Spermathecse 

 without any apparent diverticula. 



" Habitat.— St. Thomas, West Indies." 



In 1900, when ' Das Tierreich ' was published, the species was 

 split up into a type and two subspecies {intermedia and cahvoodi), 

 and four new species of Trigaster were recorded, but with only 

 two gizzards in each case. So far as I am aware, there has been 

 no true Trigaster (with three gizzards) added to the list, and if 

 that is so the worm I have received from Kew is new to science. 



1. External characters. — It would appear that the specimen 

 upon which this description is based emerged from the cocoon 

 in England, and it is therefore immature. It was of a light 

 brown colour when living, and almost transparent when viewed 

 in water under the microscope. Length 15 mm., breadth 1 mm., 

 number of segments 50. The prostomium is small and delicate, 

 and was seen when alive to be drawn in to and everted from the 

 buccal aperture. Setae arranged as in Lumbricus, i. e. four pairs 

 on each segment, but not equal in size and length in the dorsal 

 and ventral bundles. When the worm moved, it reminded one 

 rather of a planarian than of an oligochset, and it had more 

 flexibility than our British earthworms. 



2. Internal characters. — Owing to the small size of the animal 

 and its delicate structure it was possible to examine it as one 

 might examine a Tubifex or Enchytrssid under the microscope. 

 The worm was rich in blood, the dorsal vessel large, and covered 

 with chloragogen cells, which in front of the intestine formed a 

 dark mass. In advance of the gizzards the blood-vessels form a 

 rich plexus or network which enabled the red blood to suffuse the 

 whole of the organs. Pulsating hearts between the gizzards and 

 the intestine made that portion a bright red, in striking contrast 

 with the dark chloragogen cells which were here amassed. The 

 gizzards lay in segments 9, 10, 11, and the foremost one was of 

 quite a different texture from the other two, being composed of 

 fibres which crossed each other so as to give the appearance of 

 woof and warp. The principal hearts lay in segments 12-15, 

 and the intestine commenced in 19. A very striking peculiarity 

 of the intestine was observable in the fact that the hinder por- 

 tion, from about the 33rd to the 50th segment, was only half as 

 large as the foremost portion. 



