o4 ART. S. T. IKEDA : THREE NEW AND 



are not quite flat nor cylindrical but present a somewhat swollen 

 appearance. 



To judge from the arrangement of the musculature, the crop 

 and the midgut, taken together, probably correspond to the 

 anterior portion of Rietsch's " intestine intermédiaire " in Th. 

 oieptuni and to Jameson's " crop " or the anterior portion of his 

 " intestine " in the same species. However, there exists in this 

 respect a notable discrepancy in the fiict that neither the crop 

 nor the midgut in the present species is provided with the 

 siphonal groove, which does not extend, as it does in other 

 Thalassema species, farther anteriorly than the anterior end of 

 the collateral intestine. 



With regard to the wall of the part called by me the intes- 

 tine, I have found the finer structure to be essentially the same 

 as is known from the intestine of Thalassema neptuni, TJchiuoms 

 pallasii, E. iinicinctus and several Bonellia species. Only the 

 internal epithelium of the collateral intestine presents a condition 

 which seems to deserve a brief description. Fig. 41 represents 

 a portion of a cross-section through that organ, seen under a 

 high power of magnification. The internal epithelium {ept.) 

 forms a few number of longitudinal ridges that project into the 

 lumen and greatly narrow it. Each of these ridges may be said 

 to consist entirely of a continuous mass of protoplasm, apparently 

 the result of fusion undergone by the epithelial cells. The 

 nuclei are visible only near the free surface, arranged in a single 

 irregular row. Interspersed among the nuclei are a number of 

 vacuole-like spaces. All the internal parts of thé ridges consist 

 of a densely and coarsely granular mass containing numerous 

 pigment spheres of various sizes (pg.r/.)- 



