232 Freda Bage: Ihla Qiuulrivalvis. 



Male reproductive organs. t.s. 



Point at which the cuticle lining the segmental duct 



ends. X. 



Point at which the granular cells lining tiie organ (B) 

 pass into the flattened epithelial cells lining 

 (A.C.) y. 



Organ of unknown function. z. 



Figure 1. — Mouth jDarts of Ihla quadrivalvis, to show the position 

 of the tubular prominences (t.p.) situated at the base of the 

 second maxilla., and on which the segmental ducts open. 

 From a dissection. 



Figure 2. — Semidiagrammatic section through the body to 

 show the general position and relation of the parts de- 

 scribed in the text. The section is cut somewhat obliquely, 

 showing on both sides the opening of the segmental duct 

 to the exterior, and on one side the glandular organ(B),cutat 

 the place where it is most fully shown. The uiuscles (l.m. 

 and o.m.) are shown supporting the coelomicspaces(A). On 

 one side the organ of unknown function is shown (z). 



Figure 3. — Semidiagrammatic section of the coelomic spaces 

 and paxts related to them, showing the character of the 

 epithelium lining the various parts mentioned in the text. 

 The segmental duot is lined throughout by a single layer of 

 cells, over the surface of which passes a continuation oi the 

 outiole covering the external surface of the body. 

 Figure 4. — Semidiagranunatio section showing the glandular 



organ (B) opening into space (A). 

 Figure 5. — Dia^ana illustrating the parts treated in the text. 



