300 RHOPALOMENIA. 



Fig. 50 shows the animal upon a branch of Aglaophenia viyrio- 

 phyllum. Fig, 53 shows one of the cuticular papillee in section. 



The specimens from Banyuls (pi. 45, figs. 46, 47, 53) examined 

 by Pruvot may possibly belong to a distinct species, differing from 

 typical aglaophenicB in wanting the radula. They measure 30 mill, 

 long, 2J wide ; color cream-white ; form strictly cylindrical with no 

 trace of a dorsal ridge or line. The caudal sensory knob is retract- 

 ile, without a corona of spicules different from those of the general 

 integument ; it is the same with the cephalic knob (fig. 46). Always 

 occurs coiled around Aglaophenia myriophyllum, in 60-80 meters 

 depth. 



R. EisiGi Thiele. PI. 44, figs. 40-45. 



Closely allied to R. aglaophenice. Length 25, diam. somewhat over 

 1 mill. A strong hump above the somewhat attenuated anterior 

 end. Spicules similar to those of aglaophenice, but the largest seem 

 to be more strongly curved, and the smallest have no hollow (figs. 

 40-42). A rudimentary radula sheath present. Salivary glands 

 and genitalia as in aglaophenice.. 



Naples^ 



Rhopalomenia eisigi Thiele, Zeitsch. Wiss. Zool., Iviii, p. 269, pi. 

 16, figs. 123-129 (1894). 



Distinguished from R. aglaophenice by the hump on the head, etc. 

 The ventral fold is sharper, and the epithelium of the mid-gut more 

 strongly developed than in that species. 



R. ACUMINATA (Wireu). PI. 44, figs. 33-36. 



Body 9 or 10 times as long as wide, rounded in front, pointed be- 

 hind, in section triangular with rounded angles. Spicules lying 

 mainly within the cuticle, 0*5 mill, long ; those along each side of 

 the ventral furrow standing radially, 0'25 mill. long. Radula very 

 small, not occupying a cavity of the pharynx wall, composed of a 

 basal membrane and transverse rows of rudimentary teeth (or low, 

 transverse threads ?). Dorsal sense-organ oval, cleft-shaped, situ- 

 ated about 2 mill, from the posterior end. Length 28^ mill.,^ 

 breadth about 3 mill. 



Proneomenia acuminata Wiren, Kongl. Sv. Vet. Akad. Handl., 

 XXV, p. 68, pi. 10, f. 1-29 (1892). — Rhopalomenia acuminata Sim- 

 roth in Bronn, p. 231. 



