PUGET SOUND NEMERTEANS. 205 



Just in front of the nephridial region the following changes 

 occur : 



1°. Inner circular-muscle-layer becomes enormously thick- 

 ened. 



2°. Dorsal and ventral nerves commence to break through 

 the outer circular-muscle-layer and dip down toward the inner 

 layer. 



3°. Lateral nerv^e cords commence to break awa}' from the 

 inner side of the outer circular-muscle-layer and sink deeper into 

 the longitudinal layer. 



4°. Diagonal muscles commence to thin out, to disappear 

 •completely a short distance further back. 



Proboscis-pore subterminal, cephalic lacunae extend to tip of 

 head. A cephalic gland is present in type specimen. It con- 

 sists of deeply staining lobules that hang into the cephalic 

 lacunae anterior to the proboscis pore.^ Brain, with lacunae and 

 rhynchocoelom in brain region, more or less completely inclosed 

 in an inner capsule of connective tissue separated from basal 

 membrane by a thin longitudinal muscle-layer. Mesenchyme 

 scanty. 



Habitat and Distribution. In sand between tides and on 

 piles of wharves, along the west shore of Port Townsend har- 

 bor, between the wharves of the city and the railroad depot. 



Two varieties of this species were taken, which for convenience 

 •of reference will be distinguished by varietal names. 



4. Carinoma mutabilis argillina n. var. 



General form and color as in type. The entire worm was not 

 •obtained ; the largest fragment measures 1 5 cms. by 3 mm. in 

 alcohol. Differs from type in larger size, rather more powerful 

 muscular development. Excretory pore in oesophageal region 

 where inner circular-muscle-layer is still thick, and anterior to 

 •cessation of dorso-lateral vessels, i. c, slightly further cephalad 

 than in type. Mesenchyme rather more extensive, lateral halves 

 meeting in mid-ventral line behind mouth. 



1 Biirger ('95( i) ) makes no reference to a cephalic gland in C. patagonica, and 

 ^'95(2) ) is not quite sure of its presence in C. arniandi. 



