Mr. H.J. Carter on Microscopic Filaridse. 33 



in the centre of the anterior extremity ; no vulva ; anal orifice 

 at the root of the tail. Alimentary canal commencing with a 

 narrow, rigid oesophagus, ending in a much wider intestine, 

 which is continued straight through the body, of uniform calibre, 

 to the rectum, which is short, narrow, and proceeds obliquely 

 to the anus. (Esophagus surrounded by a muscular sheath, and 

 probably a peritoneal one ; but the latter is not seen in situ, and 

 the parts arc too delicate to admit of its being demonstrated by 

 their forcible expulsion, as in the adult, where it is also not 

 visible in situ, but becomes evident when the oesophagus has 

 followed the ovisac on its bursting through the body: thus the 

 peritoneal sheath of the oesophagus would appear to be undis- 

 tinguishable in both instances in situ, from being in contact with 

 the muscular sheath, while in some of the microscopic Filaridre 

 it is separated by a distinct interval (PI. III. figs. 29, 30). Peri- 

 toneal sheath of intestine continued from the constriction oppo- 

 site the union of the oesophagus and intestine to the commence- 

 ment of the rectum, where it terminates. Hepatic organ con- 

 sisting of a layer of yellowish oil-globules, which occupies the 

 interval between the intestine and its sheath from the oesophagus 

 to within a short distance of the rectum, where it disappears 

 and leaves the rest of the intestine only covered by the peri- 

 toneal sheath (fig. 6/). Organs of generation undeveloped; no 

 vulva. Size l-33rd of an inch long and 1 -633rd of an inch 

 broad. 



Obs. The transverse stria? are far more marked in the young 

 than in the adult Dracunculus, where they are but just percep- 

 tible under a high microscopic power, and appear to be identical 

 with the transverse muscular fibres, while in the young Dra- 

 cunculus they are evidently corrugations of the integument. 



Urolabes palustris, n. s. PI. II. fig. 7. 



Female. Linear, cylindrical, smooth, white or colourless, un- 

 striated transversely, gradually diminishing towards the head, 

 which is obtuse and terminated by a distinct labiate portion, 

 furnished with at least two, if not four, indistinct papillae; di- 

 minishing abruptly towards the tail, which is attenuated and 

 whip-like. Mouth in the centre of the anterior extremity. 

 Vulva a little in front of the middle of the body. Anus at the 

 root of the tail. 



Integument transparent, tough, apparently structureless, lined 

 by a muscular coat, which only becomes visible under protru- 

 sion, when the former is ruptured. Muscular coat circum- 

 scribing the peritoneal cavity, presenting on its inner surface 

 lines of oil-globules, and towards each extremity sarcoid glandi- 



Ann. if Mag. N. Hist. Ser. 3. Vol. iv. 3 



