1905.] NATURAL SCIENCES OF PHILADELPHIA. 853 



there is a fourth small or even well-developed one at the apex. Abdom- 

 inal uncini differ from the thoracic only in their small size. 



The tube measures 5 mm. in diameter with a lumen of half that size. 

 The lining is a tough mucous membrane and the exterior a thick brittle 

 coat of dark gray mud. 



The type and only specimen was taken at station 4,258, in Lynn 

 Canal, on a muddy bottom at a depth of 300 fathoms. 



Artacama coniferi sp. nov. (Plate XLIV, figs. 11 to 13.) 



This species is established upon two specimens measuring 22 and 45 

 mm. long respectively and neither of which is complete. The small one 

 consists of 20 thoracic and 17 abdominal segments, is 3.5 mm. wide in 

 the anterior part of the thorax and 2.2 mm. wide in the abdomen and 

 posterior half of the thorax, and has the proboscis protruded for 3 mm. 

 The larger example has 20 thoracic and 35 abdominal segments, with 

 the caudal end still lacking. The proboscis is 6 mm. long, the thorax 

 17 mm. long, and its anterior half 6 mm. wide, while its posterior half 

 tapers into the abdomen, which has a diameter of 2.5 mm. 



The form is club-shaped with the first ten or eleven thoracic segments 

 much enlarged, the middle of the thorax more or less abruptly con- 

 tracted and the posterior portion tapered to the abdomen which con- 

 tinues to diminish to the posterior end. 



The proboscis, which protrudes ventral to the mouth, is a large sugar- 

 loaf -shaped organ as long as the first nine or ten segments, and has a 

 basal diameter nearly equaling these. At the apex is a slender con- 

 ical process about three times as long as thick, with its end rounded. 

 Into it the retractor muscle is inserted, and it stands out prominently 

 when the proboscis is extended. At the base the proboscis is some- 

 what rugous like the peristomium, with which it is continuous. Ex- 

 cept for the rugosities the basal one-third is smooth, but the remainder 

 bears small, low, rounded papillae arranged in irregular rows, at first 

 distant, but converging distally to the apical process, where they are 

 more crowded, being separated by at most their own diameter. 



The prostomium is folded into a double horseshoe-shaped oral fold 

 with a broad, thin, median plate or membrane above the mouth, and 

 behind this a pair of thick reflexed pads which become wider dorsally 

 and nearly meet in the median line, and which bear the very numerous 

 and much crowded tentacles. From the ventral end of the group, where 

 they are mere papillae, the latter increase until they almost equal the 

 branchial filaments. Usually they are very slender with the ends 

 enlarged. 



