270 



ORDER POLYLAIMIA 



V. Order Polylaimia 



This order cannot at present be so satisfactorily defined as most of the others 

 herein represented. There probably can be removed from it sooner or later a 

 number of groups of ordinal rank, but the time seems hardly yet ripe for such 

 a removal. For the present, therefore, the genera and families ranged under 

 this name are of a more heterogeneous character than under most of the other 

 twelve orders here presented. Some slight effort has been made, here as else- 

 where, to place these new genera in the order of their family relationships. In 

 general, the genera that are first mentioned in an ordinal group, and the genera 

 placed at the end of the group, as here presented, exhibit more or less manifest 

 relationships to genera included in other orders. (See p. 217.) 



54. Cephalobium microbivorum n. sp. The wing begins near 

 the head and ends near the terminus. Its optical expression is 

 either a pair of lines, or a single line, in the middle of a field one- 

 twelfth as wide as the body. The contour of the body may 

 become crenate in the anal region. There are about thirteen 

 lateral organs in each lateral field connected with pores in 

 cuticle (see org. lat., Fig. 54). Base of the pharynx containing 

 a large, complicated and peculiar dorsal glottoid organ. No 

 amphids. The rather thin-walled intestine is set off by a collum 

 one-eighth as wide as the neck, and has a rather distinct lumen. 

 It becomes at once five-sixths as wide as the body, and in cross- 

 section presents two to four cells. From the somewhat depressed 

 anus, the narrow, cutinized rectum extends inward a distance 

 one and one-fourth tunes as great as the anal body diameter. 

 Scattered yellowish granules of variable size occur in the cells 

 of the intestine, the largest being one-twenty-fifth as wide as 

 the body. In addition, there are numerous very small granules. 

 ; The subarcuate, conoid tail tapers from in front of the anus to 

 the acute fine terminus. There is no spinneret. From the ele- 

 vated vulva, the rather small, somewhat weak vagina extends 

 inward one-fourth the way across the body. Along the middle 

 half of the body the two equal uteri contain ellipsoidal eggs 

 two-thirds as long as the body is wide, which are deposited after 

 segmentation begins. No embryos were seen in these eggs, 

 only blastulas. For the most part the ova are arranged irregu- 

 larly in the somewhat tapering ovaries. The rather strong, 

 slender, tapering, subacute spicula, when seen in profile, have 

 their proximal ends nearly opposite the body-axis. Toward 

 _J-.___l (l !i3-=i?-'___'l' > _'l-__ 8 *-_- their distal ends four slender 



stiffening pieces are apparent. 



i.z w. _!?. 74 -* *>. There is a strong, and rather 



i3TVf " solidj s t ra ight accessory piece, 

 bending back from the spicula at an angle of about 90 degrees, so that its proxi- 

 mal end lies opposite the body-axis. Near the beginning of the second quarter 

 of the tail there is a pair of lateral pores (?) similar to those on the female. 

 On the female these pores have been shown by intra vitam staining to be homol- 

 ogous with those mentioned above, and shown in the illustration at por lat. 

 Pairs of papillae on the tail of the male flattish-conoid, plainly innervated, rather 



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