442 GEPHYREA 



Bonellia. Proboscis very extensible and bifurcated at the end. 

 The body and proboscis are coloured a bright green. Two ventral 

 hook-like bristles, but no peri-anal ring. A single nephridium. 

 The above applies to the female ; the males are degenerate, and 

 live in the nephridinni or pharynx of the female. 



Three (or four ?) species of this genus are known. 



B. viridis Rolando (Fig. 220). Mediterranean, Adriatic, North Sea (Bergen). 

 B. minor Marion. Mediterranean (Gulf of Marseilles, Naples). 

 B. suhmii Selenka. Off Nova Scotia. Male not known. 

 B. fuliginosa Rolando 1 (Fig. 220). Mediterranean (Naples). 



Hamingia Proboscis not bifurcated, about as long as body. 

 No ventral hook-like bristles. One or two nephridia, which 

 open at the apex of one or two well-marked papillae. The 

 above applies to the female ; as in the genus Bonellia, the male 

 is minute and parasitic. It has two well-marked hook -like 

 bristles situated behind the genital pore. 



This genus was first described by Koren and Danielssen as 

 H. arctica. Two specimens were afterwards described by Horst 

 as H. glacialis. Later Lankester described two other specimens ; 

 he was the first to find the male in the pharynx of the female. 

 He is of the opinion that all three descriptions apply to the 

 same species, and for this the original name H. arctica must be 

 retained. 



Hamingia arctica K. and D. Two hundred miles north of North Cape and 

 in the Hardanger Fjord. 



Saccosoma. No proboscis. The body is flask-shaped. The 

 mouth and anus are terminal. The ovary is anterior, and there 

 is only one nephridium. No bristles. 



Our knowledge of this remarkable Gephyrean is very incom- 

 plete, but such as it is, it is due to the careful investigations of 

 Koren and Danielssen, who had only a single specimen at their 

 disposition. 

 Saccosoma vitreum K. and D. North of the Faroe Islands. 



Habits of the Echiuroidea. As a rule the members of this 

 group conceal their bodies in clefts and fissures of rocks and 

 stones, keeping up communication with the outer world by means 

 of their proboscis. Rietsch * describes a specimen of Bonellia 

 minor, which he placed in an aquarium, exploring with its pro- 

 1 Kecueil Zool, Suisse, iii. 1886, p. 313. 



