CAMPYLAIMUS, XENNELLA, ALAIMELLA 



233 



about one and one-half times as long as the anal body diameter, their proximal 

 ends slightly cephalated by expansion. They are rather markedly arcuate in 

 their distal two-thirds, but nearly straight in the proximal third. There seems 

 to be but a single testis. 



Habitat: Marine sand and mud, San Pedro, California. Fig. 5. 



.17 11. _ 23. "-M 92. 



6. Xennella cephalata n. sp. -33 V~ !' 2.3 "^2.2 ! " The cuticle, 

 which is of medium thickness, is traversed by six to eight longitudinal ribs or 

 wings on each side. There are at least four cephalic 

 setae, possibly six; otherwise the cuticle seems to be 

 naked. The mitriform head is set off by a distinct 

 constriction. The neck is cylindroid. The some- 

 what conoid oesophagus is at first one-ninth, near 

 the nerve-ring one-fifth, and at last two-fifths as 

 wide as the corresponding portion of the neck. A 

 final obscure swelling contains one or more nuclei, 

 which differ from all other nuclei in the organ. The 

 lining of the oesophagus is indistinct. The intestine 

 is separated from the oesophagus by a collum one- 

 fourth as wide as the base of the neck, and becomes 

 at once two-thirds as wide as the body, and in cross-section presents but few 

 cells. The anterior part of the intestine for a distance about equal to the length 



of the corresponding body-diameter has a 

 structure different from the portion that fol- 

 lows. The cells of the intestine contain 

 numerous very minute granules. The elon- 

 gated granular renette cell is about as long 

 as the corresponding body diameter, and lies 

 a little in front of the cardia. It is not re- 

 flexed. Apparently the excretory pore is 

 located near the nerve-ring. This latter is 

 oblique, distinct, and broad. The spicula 

 when viewed dorso-ventrally appear to make 

 an angle of about thirty degrees with each 

 other. The specimens were molting. 

 Habitat: "Sea-grass," shoal, two miles off Key West, Florida. Figs. 6a and b. 

 It is believed only the spinneret was missing fiom the single specimen measured. 



2. 106. 219. 4 - 5 M 866. 



The actual measurements are, ^ 19 ~ 18 ^ ^^-(?)944..i C r... 



la. Alaimella cincta n. sp. Cuticle relatively thick. The secondary elements 

 of the striae are on the limits of visibility and reach nearly 

 across the annule. There are probably six, flat, amalgamated 

 lips. The conoid neck contains an oesophagus which is more 

 or less clavate at the rear end. Near the mouth it is one-half, 

 at the nerve-ring two-fifths, and finally three-fifths, as wide as 

 the corresponding portion of the neck; its lining is indistinct. 

 There may be a faint, conoid cardia. Intes- 



tine at once about three-fourths as wide as the i __ 9 J.*_:_j fi- 



body, more or less thin-walled, and present- 

 ing but few cells in cross-section. The intesti- iy'iTf r~~n 1~f" 



nal cells contain numerous, rather uniform 



granules, regularly placed. From the continuous anus, the cutinized rectum 



