Miscellaneous. 399 



placed in a sac having the form of two truncated cones one above 

 the other ; that in which the haft plays rises nearly to the height 

 of the ring. The margins of this sac appear to be attached to the 

 haft by muscles destined to facilitate the movements of the style. 



On the two sides of the upper region of the bulb are the styligenoua 

 pouches, three in number. These are ovoid cavities, two of which 

 are placed horizontally on each side of the base of the haft, with 

 ducts which, starting from the extremity near the base of the style, 

 are directed towards its point. (I have not been able to determine 

 exactly where these ducts open.) The third was on the right, and 

 placed vertically. Most frequently they contain three darts ; but in 

 many individuals I have found four and even five, surrounded by 

 their basal ring and arranged symmetrically in accordance with the 

 longer axis of the pouches. 



I have several times observed in these pouches, as ClaparMe had 

 done in 1869 in Tetrastemma varicolor, the presence of a transparent 

 vesicle ; sometimes also I have seen this vesicle containing a dart 

 in course of formation, as has been indicated in other species by 

 Clapart'de, Schultze, and Keferstein. 



In all these Nemertians I have detected above the styliferous 

 apparatus a more or less blackish layer, which is no doubt a secretory 

 apparatus. In those individuals in which the style was in process 

 of formatioTi this layer appeared to me to be thicker ; it entirely 

 enveloped the styligenous pouches. The mass which separates these 

 pouches from the enveloping muscles is formed by fine pigment- 

 granules. 



The poison-sac follows the bulb of the style. It is rounded, and 

 the muscular layer which envelops it is much thicker than in the 

 other parts of the proboscis ; it keeps in reserve the liquid produced 

 by the glandular region. From this sac a duct starts, which traverses 

 the bulb and opens near the point of the style. 



Last comes the glandular region, which terminates the muscular 

 region, and the interior of which is filled with numerous vesicles 

 containing little granular drops of an oily appearance, penetrating 

 into the poison-sac in proportion as the latter is projected out of the 

 animal. I have always seen this part of the proboscis occupied by 

 these vesicles, just as the poison-sac was filled with the liquid which 

 has to flow from it. 



AVhen the animal has to project its proboscis we see the muscular 

 region take on a vermicular movement, which is communicated to 

 the glandular region, and carries with it the liquid of the general 

 cavity, which collects in front of the cephalic lobes and compels the 

 anterior part of the proboscis to fold like the finger of a glove and 

 penetrate into the canal which separates it from the orifice of issue. 

 The canal, formed of very powerful muscles, plays an important part 

 in the projection of the proboscis. The protractile region ])enetrate9 

 into it with difficulty ; but as soon as a part of it projects under the 

 influence of the liquids accumulated in the cul-de-sac, we see it issue 

 with very great rapidity, in consequence of the pressure of those 

 muscles upon the part which is still in the interior. 



