carmalum (after de Gr carminic acid i gram, alum 5 grams, iron-oxide amm. sulph. 0.1 



gram, distilled water 200 grams) for 2 or 3 days, rinsed them in water, and replaced them in 

 alcohol. Transverse or longitudinal sections were made; several of the animals were very brittlc, 

 a circumstance seriously interfering with the cutting, often causing the sections to be broken. 

 This brittleness often made it advisable not to take too thin sections (12.5 — 15 ua.). The 

 diagrams in perspective have been obtained by careful reconstruction on millimeter-paper of all 

 the tracings of the sections that had been made with the aid of the camera lucida, the situation 

 and size of the organs being therefore quite correct. The spicula were isolated with Eau de Javelle. 



II. DESCRIPTION OF THE NEW FORMS. 



Proneomenia. 



1. Proneomenia Weberi nov. spec. (Plate I figs. 1 — 22). 



Stat. 33. Bay of Pidjot, Lombok. 22 M. In mud. 1 Specimen. 



Stat. 45. 7 24' S., 118° 15'. 2 E. Java-Sea. 794 M. Upon Gorgonid. 1 Specimen. 



Stat. 177. 2°24'.5S., i2o°38'.5E. Between Ceram and Misool. 1633 M. Upon Gorgonid. 



1 Specimen. 

 Stat. 253. 5°48'.2 S., I32°I3' E. Near the Kei-islands. 304 M. Upon Gorgonid. 1 Specimen 



(fragment). 

 Stat. 314. 7 36' S., ii7°3o'.8E. Java-Sea. 694 M. Upon Gorgonids. 6 Specimens. 



Length 18 — 37 mm. Length-index 22 — 25. Body proximally bluntly cut off, distally 

 ending in a trunk-shaped elongation. Cloaca with 3 pairs of coeca, extending proximally. Radula 

 strongly developed with 12 — 18 rows of teeth. The salivary glands remain separated. Cloaca- 

 ducts with vesiculae seminales and receptacula seminis. 2 Strong copulation-spicula. 



East-Indian Archipelago. 10 Specimens. 



The length of the animal varies from 18 — 37 mm.; the diameter from 0.75 to 1.5 mm.; 

 the length-index therefore being 22 — 25. Two specimens are represented, 4 times enlarged, in 

 figs. 1 and 2. 



The shape is cylindrical ; proximally it is slightly thickened and bluntly truncated. Distally 

 the animal also thickens somewhat and ends in a trunk-shaped prolongation, which may attain 

 the length of 2 mm. To a certain extent we find certain resemblances between this form and 

 X'inatomenia flavens and Myzomenia banyulensis (Pruvot 4, fig. 1 and 2). The colour is dark brown, 

 often greenish. The animal has an exquisitely glittering spicular investment, the spicula intercrossing 

 rectangularly. The ventral groove is distinct. The mouth-opening is visible as a vertical slit. 



The spicula are straight or slightly curved hollow tubes, pointed at both ends (hg. 3 A.). 



1 his form fully* corresponds to that of Proneomenia neapolitana (Thiele 8 fig. 52). The little 



curved massive spicula (B) are found around the cloaca-opening in great numbers; those of 



shape C occur at the proximal and distal part of the body, whilst along the ventral groove 



