BDELLODEA niRUDINEA NEPHELOPSIS OBSCURA. 959 



in front. Ocelli eight ; two pairs on the first ling near the front, the 

 inner pair larger, well separated ; two pairs on' the sides of the buccal 

 segment, small, distant, the upper pair a little below the level of the outer 

 pair of anterior ones. Inner surface of the upper lip very rugose, the 

 sulcatious and folds diverging outwardly. Mouth large ; folds of the 

 oesophagus broad, prominent, the outer end pointed, triangular. Anal orifice 

 large, with raised borders, situated on the dorsal surface a little in advance 

 of the posterior sucker, which is large, rounded, the disk expanded, and 

 considerably larger than the pedicel. Clitellus much thickened; male 

 organ short ; protruded as a low, truncate cone, with disk-shaped end. 

 When examined by transmitted light, a row of eleven rather large, translu- 

 cent, pyriform spots may be seen midway between the dark intestine and 

 the flattened margin, which appeared to correspond with the testicles. Color, 

 above and below, dull dark brown, umber-brown, or fuscous, usually with 

 numerous obscure, narrow, longitudinal stripes of lighter and darker brown. 



Var, b, maculata. Form and size nearly as described above. Color of 

 preserved specimens greenish-yellow or clay-color, with small irregular 

 spots of black scattered over the back ; lower surface nearly plain clay- 

 color. Ocelli, eight, but often not very distinct in preserved specimens. 



Three small, acute, triangular lobes above, and alternating with the 

 upper ends of the oesophagal folds. A specimen from Fire Hole Basin was 

 much darker ; the black blotches being larger and more or less confluent. 



Wisconsin to Colorado. 



Var. b, San Liiis Valley, Colorado, common, Lieut. W. L. Marshall, 

 expedition of 1873. 



This species was first taken in Wisconsin in May, 1870, when numer- 

 ous egg capsules were also found attached to the stones along the shores. 

 These were yellowish in color, broad-oval or elliptical, terminating in a 

 point or mucro at each end, flat below, smooth and slightly convex above, 

 with a thin margin. They were 5 ram .5 to 8 mm long by 3 mm .5 to 4 mm broad, 

 Each one contained from five to ten eggs, or young leeches ; some of the 

 latter were already leaving the capsules ; these were 5 mm or more in length, 

 and even at this age, though pale in color, they had the characteristic form of 

 the adult, and the eight ocelli were distinctly visible. 



