OLIGOCH^TA 307 



Key to the genera of Enchytraidae here described: 



Oi Setae straight, or nearly so. 



&! All setae in a bundle of equal length 1. ENCHYTB^EUS 



& 2 Setae not all of equal length, inner setae of each bundle smaller than 



outer 2. FEIDEBICIA 



o a Setae sigmoid. 



& x Blood yellow or red ; testes massive 2. LUMBBICILLUS 



6 2 Blood usually colorless ; testes subdivided 4. MESENCHYTB^EUS 



1. ENCHYTR^TTS Henle. Setae straight or nearly so, all those in a 

 bundle of equal length (Fig. 484); blood colorless; large salivary glands 

 present: 10 species. 



E. albidus Henle. Milk-white worms 25 mm. long and 1 mm. thick; 

 setae nearly straight but hooked at inner end 2 to 6 in a bundle; num- 

 ber of segments 53 to 69 : New Jersey to Maine, along the seashore near 

 high-water mark under decaying seaweed and stones, also inland near 

 the shore; very common in Europe and America. 



E. socialis Leidy. Body translucent and 20 mm. long; setae 5 to 7 

 in a bundle ; mouth triangular : in groups, in rotten stumps and logs. 



Fig. 484 Fig. 485 Fig. 486 



Fig. 484 Setae of Enchytrceus (Siissw. F. Deut.). Fig. 485 Setae of Lumbricillus 

 (Stissw. F. Deut.). Fig. 486 Setae of Fridericia (Siissw. F. Deut.). 



2. LUMBRICILLUS Oersted (Fig. 485). Setae sigmoid; testes mas- 

 sive; blood yellow or red; no salivary glands; clitellum covers segments 

 .11 and 12: 15 species. 



L. agilis Moore. Transparent worms with pink or brown internal 

 organs, 16 mm. long and .4 mm. thick: Maine to Vineyard Sound, along 

 the seashore under seaweed near high-water mark. 



3. FRIDERICIA Michaelsen (Fig. 486). Setae straight, 2 to 6 in a 

 bundle and not of equal length, the inner setae of a bundle being shorter 

 than the outer; blood colorless; salivary glands present: 21 species, 6 

 in this country. 



F. alba Moore. Length 22 mm.; number of segments 58; sper- 

 matheca simple; salivary glands branched; setae long and slender: in 

 wet moss and leaves in the woods. 



F. parva Moore. Length 16 mm.; number of segments 46; sper- 

 matheca and salivary glands unbranched; 4 setae in a bundle as far as 



