264 ORDER ISOLAIM1A 



.?. ..S-Jrr ..-... 1 . 1 '*'!'... 9-. .>!.!.. 



48. Ceramonema attenuatum n. sp. l - 2 - 4 2 - 8 3 - 1>9 Each annule 

 of the thick, transparent, naked cuticle is made up of eight elements so fitted 

 together as to be reminiscent of the arrangement of corrugated roof-tiles; hence, 

 the name "Ceramonema" (see an, Fig. 48). Neck cylindroid, with minute, 

 somewhat forward-pointing setae one-fourth as long as the annules are wide. 

 The setae occur in longitudinal rows, one on each annule, but whether on each 

 of the longitudinal lines is problematical. Lips amalgamated. It is probable 

 that there are minute papillae a little in front of the anterior row of cephalic 

 setae. The very narrow pharynx joins the oesophageal lumen with little alter- 

 ation. The oesophagus gradually narrows to near its posterior part, becoming at 

 its narrowest point about one-fourth as wide as the neck; thence onward, how- 

 ever, it expands so that where it joins the intestine it is about half as wide as the 

 base of the neck. There is no distinct cardia. The thin-walled intestine 

 becomes at once two-thirds as wide as the body. Possibly its cross-section is 



v>t rnh Ifil f Ih com P ose d of as few as three or four cells. Anus 



inconspicuous; rectum fully twice as long as anal 

 $ body-diameter. Salivary glands unknown. The 

 renette appears to be a unicellular gland located 

 fflpfi immediately behind the cardiac constriction ; it is 

 about half as long as the body is wide, and, as usual, 

 ~y tapers anteriorly to join the narrow excretory tube. 

 The excretory pore is perhaps just to the rear of the 

 wph nerve - rin g- ^ is ver y difficult to observe the longi- 

 tudinal fields, owing to the highly refractive nature 

 of the elements composing the cuticle. These latter 

 join each other in such fashion as to give rise to eight 

 longitudinal lines, two of which are, of course, sub- 

 lateral and span a distance equal to about one-third 

 the width of the body. The nerve-ring surrounds 

 the oesophagus near where it is narrowest. Tail 

 conoid; terminus having a diameter about half as great as that of the base of 

 the tail. The final caudal segment of the cuticle is more than twice as long as 

 the penultimate, though it seems also to be compound in its structure. The 

 caudal glands appear to be located in front of the anus, near the place where the 

 intestine joins the rectum. From the depressed and inconspicuous vulva the 

 vagina leads inward nearly half way across the body. The reflexed portions of 

 the ovaries reach well back toward the vulva. The eggs are long and narrow, 

 though no specimens have been seen containing well-matured eggs. 



Habitat: Mud among marine algae, shores of Kingston Harbor, Jamaica. Sub- 

 limate to balsam. The male of another undescribed species has stoutish, taper- 

 ing, subacute, rather frail spicula, accompanied by a more or less arcuate, rather 

 slender, frail, simple accessory piece half as long. There are no supplementary 

 organs. This undescribed species is so similar to C. attenuatum that it is believed 

 the male of attenuatum will be found to present similar features. Fig. 48. 



.4 4.8 . 7.8 "<4<> 1S 92. 



49. Bolbonema brevicolle n. sp. i-*' ' '*$'' ' V? U* 1 ' 3 " Neck conoid. 

 The walls of the pharynx are a little more strongly cutinized than those of the 

 oesophagus, especially toward the minute mouth opening. The cylindroid 

 oesophagus is about three-fifths as wide as the base of the head, but expands 

 finally to form the pyriform cardiac bulb, which is about four-fifths as wide 

 as the base of the neck. This bulb has no distinct valve, though the cutinous 



