TRIPYLIUM, XYALA 



289 



xtaim 



conoid, then cylindroid in the posterior two-fifths, where it is one-eighth as 

 wide as at the base. Terminus apiculate, bearing a simple, symmetrical spin- 

 neret. The three broadly-saccate caudal glands are packed into the anterior 

 two-fifths of the tail, and empty by means of separate ducts. Three pairs of 

 conoid, subacute, ventrally submedian papilloid setae occur on the tail of the 

 female, one pair near the anus, one near the middle of the tail and one at the begin- 

 ning of the posterior fourth. Midway on the tail there is a dorsally submedian 

 pair of setae. The finely-granular lateral fields are half as wide as the body. 

 There appears to be an elongated renette cell one body-diameter behind the 

 neck; it is one-fifth as wide as the body. From 

 the large, conspicuous, elevated vulva, the 

 vagina, also large, extends inward half way across j^y^ 

 the body. Its wall is cutinized. There is no 

 posterior vestigial portion to the sexual organ. 

 The straight uterus contains twelve or more 

 already liberated embryos. Ova are arranged 

 single file. The simple, rather frail, slender, 

 uniform, acute spicula are arcuate distally. 

 They are three-fourths as long as the tail, and at 

 their widest, about one-tenth as wide as the cor- .>. 

 responding portion of the body. Their proximal 

 ends seem to lie more or less dorsad from the 

 body-axis. The simple, frail, very slender, arcu- 

 ate accessory piece is more or less obscure in alco- 

 holic specimens. It lies parallel to the spicula 

 and its proximal end appears to be dorsad from 

 the body-axis. There are three pairs of very flat, 

 conoid, innervated, inconspicuous, nearly ven- 

 tral papillae on the tail, one at the beginning of 

 the fourth fifth, and two at equal distances 

 between it and the anus. The ejaculatory duct 

 is one-third, the testis two-thirds, as wide as 

 the body. Only the narrow blind end of the 



testis, for a distance equal to one body-diameter, \-^ j^ ^ ~li ^frf"* 1-1 " 



is reflexed. In one specimen, the spicula were 



more or less compound. jj| ^3 TT~~ ^i Tz~ > 0-9 



Habitat: Found in the gills of the Land Crabs, 



Gecarcinus ruricola and Cardisoma guanhumi, Jamaica. Collected by Dr. Chas. 

 B. Wilson, Westfield, Mass. This genus differs from Monhystera as follows: (1) 

 Male has caudal papillae; (2) Has a cardiac bulb or pseudo-bulb; (3) Is vivip- 

 arous; (4) Is parasitic in crabs; (5) Has three biting edges to the segments of 

 the pharynx. Fig. 71. Syn. Monhystera carcinicola Baylis. 



72. Xyala striata n. sp. Cuticle with numerous wings, especially anteriorly, 

 where there are sixteen, increasing to about thirty-two on the head; behind the 

 vulva the number is twelve, at the terminus four. Contour dentate. There are 

 a few cervical setae, about as long as the body is wide, occurring in groups of 

 four; no somatic setae. Lips thick, armed with three, mandible-like odontia, 

 or onchia, somewhat flap-shaped, and apparently very mobile. Pharynx simple, 

 regular, more or less conoid, large and long, three-fourths as wide as the head, 

 having the form of a deep cup. There is a distinct, transverse, cutinized raised 



