282 PROCEEDINGS OF THE ACADEMY OF [April, 



where the last inch or so is rather soft and semicollapsible. For the 

 entire length the tube is marked with annular lines which, on a tube 

 198 mm. long, are 6.5 mm. apart at the small and end 5 mm. apart 

 at the large end. These annulations are formed by the exposed edges 

 of the successive layers of material, which are laid down on the inside 

 and project beyond the orifice to a distance ec{ual to that between two 

 rings. Thus a tube showing thirty-five rings has probably been 

 constructed of as many successive layers of material. 



Both orifices are guarded against intrusion by several sets of soft 

 membraneous valves, usually three or four at the large end and proba- 

 bly as many at the small end. These are placed in pairs consisting of 

 a wide dorsal and a ventral flap or pocket attached obliquely to the 

 inside of the tube in such manner that the free borders directed toward 

 the orifice meet in the middle and thus effectually bar against entrance, 

 while yielding readily to pressure from within. Presumably, should 

 a worm leave its tube it would itself be debarred from re-entering. 

 One small tube (110 mm.) has the orifice ornamented with a few 

 foraminifera shells, sea-urchin spines and small pebbles. 



Evidently the tubes wear away at the small end, the worm occupying 

 the newer parts and building extensions at the large end and at the 

 same time removing old valves and replacing them by new pairs. 

 It is evident also that the length of additions decreases as the tubes 

 become larger and that there is much individual variation in this 

 respect. 



Old tubes are always covered with a friable black incrustation, 

 except on the newer parts at the large end, and especially adherent 

 at the rings. 8ome of them also bear growths of hydroids and an 

 occasional barnacle {Scalpellum proximum Pilsbry) small tunicate 

 (Styela) or small actinian {Sagartia sp.) 



Found at only one station, but there in abundance: 4^387, vicinity 

 of San Diego, Lat. 32° 32' 40" N., Long. 118° 04' 20" W., 1,059 fathoms, 

 green mud. 



LUMBRINERID^. 



This is another fairly well-represented family and from the point 

 of view of geographical distribution is interesting because, more than 

 any other family, it resembles the fauna of the southern Pacific coast 

 of South America. This resemblance is seen not alone in the fact 

 that the two regions possess two species in common, but also in the 

 resemblance of other species which are distinct. 



