BY JAS. P. HILL. y 



CMvlom (figs -i, 6, 7, 8, sp.) is related exactly as in the desciibed 

 species. It appears, in my prepai-ations, when it comes to lie 

 directly on the sides of the proboscis gut as a deeply staining 

 layer with dark staining nuclei in its middle region (fig. 7, sp.), 

 the cell l^odies of which are not recognisable. On the surface of 

 the glomerulus it presents essentially the same appearance of a 

 deeply staining granular layer with numerous dark staining nuclei 

 on its inner face (fig. 6, sp.). 



On the outer side of the splanchnic epithelium there is a layer 

 of tissue of a spongy appearance (figs. 6 and 7, ct.) which is 

 directly continuous both above and below with the fine connective 

 tissue of the proboscis coelom (fig. 4, ct.). This layer corresponds 

 to the characteristic layer described by Spengel-'' on the surface 

 of the glomerulus in Ft. sarniensis, and which he considers as 

 the inner limiting layer of the connective tissue of the proboscis. 

 Round the central proboscis organs there is always in sections, as 

 in the described species, a space free from connective tissue and 

 representing the proboscis cc^lom (figs. 5 and 8, phc). Posteriorly 

 towards the proboscis neck the proboscis coelom is divided, as in 

 the other species, on the dorsal side through the heart bladder 

 into two dorsal proboscis pockets (fig. 9, c/p.), and on the ventral 

 side through the ventral septum into two smaller ventral pro- 

 boscis pockets (fig. 9, vp.). The ventral septum (figs. 3-5, 8, vp)s.) 

 has in this species anterior and posterior free edges which run 

 obliquely backwards, w^hile its dorsal and ventral edges are 

 attached to the proboscis gut and the outer wall of the proboscis 

 respectively so that the septum is here four-sided and not 

 triangular as in Ft. ininuta. In its structure it is essentially 

 similar to that of Ft. minuta. It consists of a central membrane 

 carrying blood vessels, on either side" of which there is a laj^er of 

 muscle fibres — the ventral portion of the fibres of the dorso- ventral 

 muscle plate; on the dorsal side, the fibres of the same plate caii 

 be distinctly recognised on the lateral walls of the heart bladder, 

 below the splanchnic epithelium (figs. 3 and 5, else). 



" Loc. dt. p. 101. 



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