254 PROCEEDINGS OF THE ACADEMY OF [Vol. LXXV 



tip. Posteriorly they become erect and much longer, some of 

 them equalling the diameter of the body. Abdominal uncini 

 about twenty in each torus. Smaller than thoracic uncini, with 

 one large stout tooth below and above it usually four vertical rows 

 of eight or nine very small closely crowded teeth. 



The specimens removed from tulles were macerated and very 

 fragile, rendering complete description impossible. The type (in 

 four pieces) is about 41 mm. long of which the gills are 7 mm. and 

 thoracic diameter 3.3 mm. A cotype is 17.5 mm., gills 6 mm., 

 thorax about 3 mm., diameter 1 mm., thoracic segments 8, abdomi- 

 nal over 50. 



Tubes attached singly to tubes of PseudopotamiUo ; terete, 

 except for the attached side which is flattened or concave, con- 

 forming to the sabellid tube. Length of one 49 mm., diameter at 

 mouth 4.2 mm., tapering regularly to less than .5 mm. at basal 

 end. Tube slightly tortuous, stony, surface marked with circidar 

 growth lines, sometimes conspicuous, white stained with yellow. 

 Another tube measures 65 mm. long and only 3.6 diam. at the 

 mouth, the distal half being nearly uniform. Some are nearly 

 straight others more tortuous or even bent back sharply on them- 

 selves. 



Station 4433, off Santa Rosa Island, 243-265 fathoms, green 

 mud. 

 Hyalopomatopsis occidentalis Bush. 



A number of tubes and included worms are undoubtedly of this 

 species which the form of the collar setse would seem to place 

 rather in the genus Zopyrus. The soft ovate operculum has an 

 orange or brown colored internal vescicle, a thin opake and possibly 

 calcified terminal disk, and in one case two small simple spines which 

 may be the result of injury. 



The tubes are attached for nearly the entire length to the tubes 

 of larger annelids and calcareous bryozoans. They are 20-30 

 mm. long and measure at the aperture .8 mm. in transverse and 

 1.2 mm. vertical diameter, the difference being due to a prominent 

 flange which runs along the outer face for its entire length, here 

 and there, rising into irregular projections. The attached face is 

 flattened and often spreading. Surface wrinkled with irregularly 

 transverse growth lines of varied prominence, with deepened valleys 

 at fairly regular intervals, giving a narrowly fenestrated appearance. 

 At the mouth some tubes bear three projecting spines. White, 

 stony, opake, but some of the smaller tubes translucent. 



Station 4431, off Santa Rosa Island, 38-45 fathoms, mud and 

 coarse sand. 



