Of the circulatory system I only mention the dorsal sinus, which takes its course 

 proximally for a considerable distance and is also found distally to the pericardium; besides 

 two lateral sinuses, originating in the distal offset of the animal. 



Xo doubt we have to do with a species of Proneomenia. This species chiefly differs from 

 the type of the genus in its radiila, salivary glands, cloaca, cloaca-ducts, copulation-spicula and 

 shape of the body. It cannot be classed among either of the ten known species of Proneomenia. 



2. Proncovienia longa no v. spec. (Plate i figs. 23 — 40). 



Stat. 211. 5°4o'.7S., I20°45'.5 P-. Near the isle of Saleyer. 1158 M. 2 Specimens. 



Length-index 37 — 50. Colour varying from yellow-white to light brown. Posterior end 

 elongated trunk-shaped as it is in Proneomenia Weberi. Numerous pointed spicula in many 

 layers upon each other in a thick cuticle. Papillae large and vesicular. Radula polystichous, 

 up to 24 rows; the teeth of the middle-rows are broad, the others are long, either pointed, 

 clubbed or hooked. 2 Long salivary glands, which remain separated. Cloaca-ducts each provided 

 with vesiculae seminales and a vesicular receptaculum seminis. 2 Large copulation-spicula or 

 numerous small ones. 



East-Indian Archipelago, i Specimens. 



Each of the specimens has to be treated separately. 



The length of the first' specimen is 62 mm., the diameter 1.25 mm. The length-index 

 is therefore 50. The colour is white, somewhat yellowish, glittering owing to spicula, intercrossing 

 rectangularly. The ventral groove is distinctly visible. The hinder part is elongated as is the 

 case with Proneomenia Weberi, though in a slighter degree (cf fig. 23). 



The spicula are of the ordinary shape, but they are a little larger than those of 

 Proneomenia Weberi ; they lie often flat against the body-wall. Along the ventral groove and 

 around the cloaca-opening spicula like those of fig. 3 B and D are found. 



The whole of the tolerably thick cuticle is beset with spicula in many layers upon 

 each other. Numerous papillae pierce the cuticle; they belong to the multi-nucleated type and 

 are met with upon thick stalks. The full-grown papillae are vesicular, round, with some nuclei 

 at the base, surrounded by cytoplasma, which extends along the wall of the vesicle and also 

 travels through the vesicle in fine threads. The stalk shows several nuclei and is of a threadlike 

 structure. The papillae only appear after the formation of the stalks ; young papillae are never 

 found in the immediate vicinity of the hypodermis, but always more towards the outside of the 

 cuticle ; thus nearly all the papillae are situated at one level. At the end of each stalk a 

 little knob is formed, multinucleated and with strongly granular cytoplasma ; in a more advanced 

 stage the knob increases in size and openings occur in the cytoplasma ; when full-grown the 

 cytoplasma together with the nuclei removes to the wall, only to traverse the vesicle in a 

 threadlike shape. At last the vesicles break though the cuticle and open (fig. 25). 



A dorso-terminal sense-knot is present. 



The ventral groove and folds are like those of Proneomenia Weberi. The ■'Flimmrr- 



