224 36 



Three pair of longitudinal muscles for the wheel-organ and one pair acting as a 

 retractor for the foot. Testis very large, globular, with two kinds of spermatozoa; a 

 thick ductus seminalis covered with cilia; genital opening upon the first foot seg- 

 ment; the opening surrounded by a wreath of cilia. Two prostata glands; above the 

 testis a globular mass of opaque concrements. Two small foot glands. Size of male 

 180/(.; of female 250—330;«. Time July. 



Diglena forcipata. Ehrbg. 



Male: Weber 1897 p. 94. 1898 p. 487 PI. XIX fig. 8. 



Weber (1897 p. 94 PI. IV, fig. 2) has described and figured the male. 



It is of almost the same form as tlie female and also almost of the same size. It termin- 

 ates in two long toes, widely spread and separated at their base by means of a little probosci- 

 form tubercle. As in tlie female the body is covered with a rather thick, hyaline cuticle, 

 representing a sort of lorica; this is restricted to the dorsal side and ending a little below 

 the forepart of the body; behind it reaches the base of the foot. The head is curved down- 

 wards and the coating with cilia reaches the niveau of the mastax. The forepart of the 

 body carries two strong transversal folds, the one passing over the dorsal antenna, the other 

 passing over the end of the brain. The foot is thick, tlie footglands are well developed, pyri- 

 form. The wheel-organ is a large, ventral plate, covered with cilia, concave. Four longitudinal 

 anterior, two longitudinal posterior and five transversal muscles, forming regular folds in the 

 skin. No proboscidiform tubercle at the front of the head as in the female. No trace of ali- 

 mentary canal. Two excretory canals each carrying three vibratile tags open upon eacli side 

 of the penis. Tlie brain is oblong with two frontal eyes. A brilliant point above the brain is 

 observed; whether this is a dorsal antenna is doubtful. The testis is relatively small; the penis 

 is terminated by a crown of small stiff cilia. Prostata glands are not observed but yolkmasses 

 above tlie testis. 



Diglena grandis Ehrbg. 

 Tab. I, fig, 7. 

 Description. The male has almost quite the same form as the female and 

 is but little smaller. It is cylindrical, tapering behind and also a little in front. 

 Cuticula extremely thin and hyaline, provided with a system of regular longitudinal 

 folds. It is thickest dorsally and in the middlepart of the body; forepart and foot 

 can partly be drawn into the middlepart. No chitinous arched plate as in the female. 

 The body terminates in two long acute toes. Brain large; it gives off a nerve for the 

 dorsal antenna ; lateral antennæ I have not been able to observe. Two red eyes placed 

 very near each other. Wheel-organ a large disc, placed almost vertically to the longi- 

 tudinal axis, highest in the middle and drawn out dorsally and ventrally in small 

 auricles. It is surrounded by a wreath of long cilia. No particular styli observed. Of the 

 alimentary canal there is only present the connecting band between testis and wheel 

 organ. The two lateral canals carry three or four pairs of vibratile tags; there is no 

 contractile vesicle. Testis pear-shaped large; ductus seminalis without cilia. Opening 

 for the copulatory organ at the posterior border of the last foot segment. The co- 



