120 G Canadian Arctic Expedition, 1913-1918 



Family HALCAMPID^E Andres, 1884. 

 Ilyanthidce (pars). Many authors. 



Column usually narrow and much elongated, generally without a definite 

 basal disk or with a very small one; most often the base is pointed, with or with- 

 out a central pore Tentacles usually few (8 24) ; most frequently 12. Mesen- 

 teries few, hexamerous; most often only 6 or 12 pairs; all may be perfect and 

 fertile ; those of the second cycle may be imperfect ; sometimes the mesenteries 

 exceed the number of tentacles. Sphincter muscle feeble, diffuse, or lacking. 

 Mesenteries usually have a strong, often narrow or circumscribed, longitudinal 

 muscle. A conchula may be either well developed or lacking. 



Sub-family HALGAMPIN^) Verrill. New name. 



Halcampidae which lack a conchula and apparently a pore at the aboral 

 end of the body. Scapus sulcated, it may be naked or it may be covered with 

 a loosely attached epidermal coating consisting mainly of mucous, fine sand, etc. 

 Tentacles usually 12, sometimes 10, 14, 20, or 24; mesenteries 12 to 24; 12 

 usually perfect and fertile. Longitudinal mesenterial muscle strong, restricted. 



Genus Halcampa Gosse. 



Peachia (pars) GOSSE, Trans. Linn. Soc., XXI, p. 271, 1855. 

 Halcampa GOSSE, Ann. and Mag. of Nat. Hist., 3rd series, i, p. 418, 1858; 

 Actinologia Brit., p. 246, 1860. ANDRES, op. cit., p. 100, 1884. 



Column very contractile, much elongated and slender in expansion, occupy- 

 ing holes in the earth or among rocks, etc., but able to creep about, adhering 

 by the sides.; in contraction irregularly cylindrical, often with constrictions; 

 column-wall membranous throughout, translucent, with or without adherent 

 sand, etc. Base capable of being enlarged and greatly distended, without a 

 distinct disk, but capable of adhering slightly by its surface to foreign bodies 

 by very minute sucker-like organs; apparently imperf orate. Tentacles 12, 

 rarely 10, short, in two cycles. Perfect mesenteries, usually 12. They are 

 very thin next the wall, but near the middle have a very strong, longitudinal, 

 muscular thickening, which narrows both above and below. The peripheral pores 

 of the mesenteries are large and well defined; six pairs are imperfect. 



Halcampa duodecimcirrata (Sars). 



Edwardsia duodecimcirrata M. SARS, Nyt. Mag. Nat. Hist., VI, n. 10, p. 142, 

 1851. MOBIUS and MEYER, Weig. Arch. f. Naturges., Jahr. 29, b. 1, p. 70, 

 pi. Ill, figs. A, D, 1863. 



Edwardsia farinacea (pars) VERRILL, Amer. Journ. Sci., Vol. VII, pi. VIII, fig. 5, 

 1874 (not fig. 4, nor the text). 



Halcampa farinacea (pars) ANDRES, op. cit., 1884, p. 102. 



Plate XXI; Figures 1, 2, 2a. 



Column changeable in form, often nearly cylindrical, at other times swollen 

 in the middle or posteriorly, capable of contracting to less than half its full 

 length. Column is usually covered with scattered, feebly adherent, fine grains 



