304 MYZOMENIA-NEMATOMENIA. 



M. BANYULENSIS (Pruvot). PL 47, figs. 74-77. 



Body much attenuated, 30 mill, long, 1 wide ; brilliant reddish- 

 purple, with silvery reflections due to the colorless layer of spicules, 

 the young paler, somewhat orange, there being less red pigment, 

 allowing the yellow color of the intestine to show through by trans- 

 parence. Spicules of two kinds: wide and flattened (fig. 77) 

 applied to the cuticle by the notched base, and imbricating regularly 

 from below upward, over the entire surface ; between them are ir- 

 regularly placed club-shaped spicules (fig. 76), less numerous and 

 on the ventral surface passing into a third type (76), which are 

 winged, and form a row projecting on each side of the pedal groove, 

 which is protected by their depression when the animal is contracted. 

 There is a dorsal keel, formed solely by the converging spicules at 

 the median line. 



Coiled around stems of Lafoea dumosa, Banyuls and Roscqff, in 45 

 300 meters depth ; also Naples (Thiele) and Plymouth ^Garstang). 



Dondersia banyulensis PRUVOT, Arch. Zool. Exper. (2), viii, p. 22 ; 

 ix, p. 715, 777, pi. 25, f. 1 ; pi. 26, f. 8, 9 ; pi. 28, f. 20-33a; Comptes 

 Rendus, cxiv, p. 1214 Myzomenia banyulensis SIMROTH in Bronn, 

 p. 231, pi. 8, f. 1-13. THIELE, Zeitsch. Wiss. Zool., lviii,p.273,pl. 

 16, f. 132-143. GARSTANG, Proc. Malac. Soc. Lond., ii, p. 124, pi. 10, 

 f.4. 



Genus NEMATOMENIA Simroth, 1893. 



Nematomenia SIMR., Klassen u. Ordn. des Thier-Reichs, p. 232. 



Body proportioned like Myzomenia. Spicules leaf shaped. Rad- 

 ula wanting, its sheath present. Oesophagus short. Four salivary 

 glands. Length 40 times the breadth. 



N. FLAVENS (Pruvot). PI. 47, figs. 78-82. 



Externally similar in form to Myzomenia banyulensis, having the 

 same cephalic "bib" of erect spicules (fig. 79), with fine tactile 

 bristles along the whole buccal margin (fig. 79) ; the same dorsal 

 carina formed entirely by the converging spicules, and the same more 

 projecting border of spicules along the pedal groove. But the body is 

 a beautiful citron-yellow from the shining through of the intestine. 

 The tissues appear more delicate, the body less rigid, susceptible of 

 being more closely coiled than the Myzomenia. The spicular cov- 

 ering resembles in general that of M. banyulensis, being composed 

 of flat, upwardly imbricated spicules, very readily detachable from 



