10 IT. F. NIERSTRASZ. 



ones, cousiderino- in the first place the exact structure of th« radula and salivary- 

 glands. I i^ropose the following division : — 



FAMILY PRONEOMENIIDAE. 



Index— at least — G. Cuticle thick, with many layers of spicules, by far the greater part of which is 

 pointed and hollow. Epidermal papillae present. One or more dorso-tcrminal sense-organs. Radula and 

 salivary glands present. Gills are wanting. 



A. Radula multiserial. Salivary glands tuljc- or bag-shaped. 



Proneomeiiia llubrecht. 



a. Radula with basal membrane. Salivary glands tube-shaped, uniting before opening 



out into the digestive tract. Receptacula semiuis strongly folded, glandular. The 

 spicules remain connected with the epidermis l)y multinuclear stems. Abdominal 

 spicules present. Index U-ll. " 



Proneomenia sliiiteri llul)r. (4.) 

 (= lanffi Ueuscher), 



Barent's Sea, Spitzbergen. 

 70-160 fathoms. 



b. Riidula witli l)asal membrane. Salivary glands tube-shaped, (ipening out separately. 



Receptacula seminis vesicular or tube-shaped. 



a. With ■ abdominal 'and cloacal spicules. Receptacula seminis vesicular. 

 One dorso-terminal sense-organ. Index 22-50. 



Proneomenia weheri Nierstr. (6, p. 2.) 



East-Indian Archipelago, 22-1633 M. 

 Proneomenia longa Nierstr. (6, p. 7.) 



Saleyer, East Indian Archipelago, 11.58 M. 

 p. Witliout abdominal, with cloacal spicules. Receptacula seminis vesicular. 

 Two dorso-terminal sense-organs. Index 10. 



Proneomenia discoveriji Nierstr. 



77° f)0' 30" S., 16.5° 40' 5" E. 100 fathoms. 

 y. Without abdominal or cloacal spicules. One dorso-terminal sense-organ. 

 Receptacula seminis vesicular or tube-shaped. Index 9-18*5. 

 Proneomenia valdmae Thiele (16.) 

 3° 7' S., 40° 45' 8" E. 74.s M. 

 Proneomenia acuminata Wiren (18, p. 68.) 



"West India. 300 fathoms. 

 Proneomenia haimiemis Heath (1.) 

 (? insufficiently known.) 

 Hawaian Islands. 

 Proneomenia t/erlachei Vols. (10, p. Hi.) 

 70° S., 80° 48' W. 500 M. 



c. Radula without basal meml)rane. Salivary glands tube- or bag-shaped, opening out 



separately. Receptacula seminis vesicular. 



a. AVith abdominal and cloacal spicules. Salivary glands tube-shaped. 

 1-3 dorso-terminal sense-organs. Index 6. 



Proneomenia vai/ans Kow. a. Mar. (5, p. 2'.).) 

 Mediterranean. 

 ji. Witli abduminal, without cloacal spicules. Salivary glands liag-shaped. 

 Receptacula seminis numerous, often lobate. One dorso-tcrminal sense- 

 organ. Index 1 1. 



Proneomenia /hulensis Thiele (14.) 

 80° .s'N., 16" 55' E. 4,so M. 



