1901.] NATURAL SCIENCES OF PHILADELPHIA. 739 



Fig. 57. — Portion of a cross section through the testis, showing the mar- 

 ginal spermatogonia. X 6()4. 



Fig. 58. — Spermatozoa, the middle piece seen in side view and appearirg 

 bilobed. A minute point is present at the tip of the head. Iron-haima- 

 toxyliu, strongly destaiued. X 1120. 



Fig. 59. — Spermatozoan, and a detached middle piece, m.h., which is four- 

 iobed. Iron-hiBniatoxyliu, not strongly destaiued. X 1120. 



Fig. 60. — Portion of a cross section through the body wall and ovary, 

 showing an encysted stage of a parasite, P*^?'. The stiiated cuticle, Ctl., is 

 surrounded by a delicate membrane. Two egg nuclei, N., are to be seen in 

 the cytoplasm at the base of the cyst.'^ The nucleus within the cyst, N.Far., 

 is amcEboid. X 320. 



Fig. Gl. — Cross section of an ovum infected with a young (?) stage of a 

 parasite, Par. x 604. 



Plate XLIV, Fig. 62. — Part of a cro^s section of the body wall through 

 one of the •' lateral grooves," L. G. The individual cells of the groove are 

 not clearly distinguishable with this magnification. 95 per cent, alcohol. 

 X 320. 



Fig. 63. — Portion of a cross section through the body wall of Partipolia 

 mii'antiaca Coe, showing the "lateral gioove." The " lateral groove " is 

 here everted, and appears as an elevation above the general surface level. 

 The cutis glands, C>i.G[.„ of the "groove" are large and ai e not found in 

 other parts of the section. X 40. 



^'The reference line from Ctl. only extends as far as the egg membrane, 

 instead of to the cuticle within. 



