70 ART. 4. r. IKEDA : 



the proboscis is about 2 cm. long and truncated at the apex. 

 The skin is of a slightly pinkish orange-yellow which becomes 

 reddish on the edges of the proboscis. Large papillse are scat- 

 tered irregularly over the entire body-surface, more thickly at 

 both ends than in the middle. The two golden-yellow ventral 

 hooks are relatively small in size and are supplied with well 

 developed radial muscles {em, Fig. 99). The longitudinal dermal 

 muscle is perfectly continuous. There exists only one pair of 

 comparatively long (about 20 m??^.) segmental organs (so), attached 

 to the bod}'- wall just behind the ventral hooks. The opening of 

 the organs appears as a large funnel {fn) unprovided with spiral 

 lobes. The pharynx as well as the œsophagus are entirely with- 

 out a mesentery or muscular strands. The anal glands are about 

 as long as the body proper ; the ciliated funnels, sparsely dis- 

 tributed over the surface, are relatively small and short-stalked. 

 No rectal gland is present. 



There have hitherto been known four Thalassema species 

 which, like the present, have a continuous longitudinal muscle 

 and only one pair of segmental organs, viz., T. diaphanes 

 Sluiter, T. fœx Selenka, T. gigas Müller and T. Lankes- 

 teri Herdman. The first further agrees with the present 

 species in one other point, viz., that the segmental organs lack 

 spiral lobes ; nevertheless, the former shows several important 

 characters which are entirely wanting in the latter. Of the three 

 remaining species mentioned, T. gigas seems to be nearest to the 

 present species in respect of general internal anatomy ; but, that 

 species, as figured and described in detail by Greeff (14), 

 should be easily distinguishable from the new species here 

 described, owing to the differences in size, color and general 

 features of the entire worm-bodv. 



