15 



often mature, are probably not fully cleveloped. While they were alive, I could at least in none 

 of them detect the two said colours, though all the specimens show the prominences in more 

 or less degree. The interior structure however takes away every doubt regarding amnity. 



The cuticle is thick, especially in the foremost and hinder portion ; in the middle region 

 of the animal it is comparatively much thinner. It is traversed by many layers of spicula. The 

 prominences are formed by a thickening of the cuticula. The spicula are of the usual shape 

 (fig. 62 A), but are comparatively small and of unequal size. On the prominences they are 

 somewhat larger. The cuticula being thicker there, and the large spicula mostly standing erect, 

 the prominences are immediately conspicuous. The spicula of shape B and C are found along 

 the ventral groove. 



There are numerous papillae upon long stalks, not dilating vesicularly. On the prominences 

 they are especially numerous and accumulated, a fact, giving rise to the question whether perhaps 

 any special function has to be attributed to the prominences. 



A dorso-terminal sense-organ is present; tolerably strong muscular bunclles surround it, 

 by means of which it can probably be stretched and retracted. Around this very small, slightly 

 curved spicula are arranged. 



Around the cloaca-opening, where the body-wall forms a shallow furrow, special spicula 

 are also found (fig. 62 D) in considerable numbers, whilst there the papillae are numerous too 

 and of a somewhat different shape. 



Behind the "Flimmerhöhle" the ventral fold has five folds, or rather three, the middle 

 and larger one being in some specimens more or less distinctly divided into three : there being 

 in that case five folds. More distally there are only three folds (fig. 81). Just before the cloaca- 

 opening the ventral folds terminate. The "Flimmerhöhle" is not spacious. The folded wall is built 

 up of strongly ciliated cylindrical epithelium ; amongst its cells those of the "hintere Bauchdrüse" 

 are seen to open out; these are also found all along the ventral groove. The "hintere Bauch- 

 drüse" is not so strongly cleveloped as it is in other forms: it only encircles the "Flimmerhöhle" 

 but does not extend around the pharynx. The "vordere Bauchdrüse" is not present, at least 

 cannot positively be demonstrated. Here and there among the other glandular cells crystalline 

 cells are found, reminding of the cells of the "vordere Bauchdrüse" of the other Neomeniidae. 



The cloaca is of a simple structure. It is a more or less heartshaped space, opening on 

 the ventral side of the animal through a narrow slit. The wall is strongly folded and lined 

 throughout by a strongly ciliated cylindrical epithelium, with oval nuclei. The cloaca divides into 

 two parts: the dorsal and larger portion giving entrance to the rectum, the ventral and smaller 

 one to the precloacal organ (fig. 79 a and 6). 



The digestive canal furnishes the greatest peculiarities, see fig. 63. The wide mouth-slit 

 leads into the large mouth-cavity. Very strong "Mundleisten" occur, whilst cirrhi are found in 

 space a. These are arranged in bundies. Each bundie is placed upon a small epithelial fold ; so 

 that there are a great many bundies isolated from each other. Some of the cirrhi of these bundies 

 have one common base, some stand free from each other. In some specimens the green granules 

 of which we spoke in Proneomenia Weberi are met with. The "Mundleisten" are strongly built 

 and entirely filled with connective tissue. Further there still remains to be mentioned a little 



