CLASSIFICATION OF ACTINIAKIA 251 



ancestor than most forms, and live a more or less burrowing life. Size 

 variable, predominating shape vermiform, this being attained in gieater 

 or less degree in different cases ; the diameter of the body in some fonns, 

 or at least in some states, bearing a fair proportion to its length. There 

 is no atlherent base, the aboral end being a physa, which does sometimes 

 adhere to small objects. There is little or no sphincter, but if present 

 it may be endodermal or mesogloeal. Cinclides often present. Number 

 of tentacles usually sauall, even at greatest not passing about forty ; 

 not more than one communicates with each endocoel and exocoel. 

 Number of mesenteries similarly limited, and they are either all macro- 

 cnemes or else a division into macro- and microcnemes is to be found — 

 with an interinediate condition in the case of Peachia. Secondary 

 mesenteries develop in the exocoejs of the primaries. Sometimes the 

 larvae seem to be parasitic on medusae. 



Family 1, Halcampidae, Andres, 



Used here in the general sense of Andres, 18S3, p. 312. 



Tlyanthidae as used by Gosso, pro parte. 



Incliuling Halcampoidinae, Appellof, 1896, p. 18 ; Hal- 

 canipomorphinae, Carlgr., 1898, p, 88 ; Halcanipinae, Carlgr., 

 1898, p. 88 ; Monaulidae, Hertw., 1882, p. 104 ; Halianthinae, 

 Kwiet., I89(i ; and ' Fenj a ' and ' Aegir '. 



Athenaria of more or less vermiform shape, with or without suckers or 

 papillae on the body, with or without cuticle or incrustation, ('in- 

 clides may occur in the physa. Tentacles eight to twelve, fourteen, 

 twenty, or more, and wdth other variations, their longitudinal muscula- 

 ture ectodermal. Sphincter absent, weak mesogloeal, or weak endo- 

 dermal. The mesenteries have as their main feature six pairs of 

 macrocnemes, but there are variations ; the full six pairs may not be 

 developed, or there may be one or two unpaired macrocnemes in addition 

 to them. Microcnemes are sometimes present, their number varying. 



Genera: Halcam])a, Halcampoides, P ent ac- 

 tinia , S c y t o p h o r u s . 



Halcampa, Gosse, 1858, 



See Carlgren, 1898, pp. 87-8 ; Kwietniewski, 1896, p. 585 ; 

 Haddon, 1 889, p. 885 ; Carlgren, 1 900 (on P e n t a c t i n i a), 

 p. 1170, &c, ; and Stephenson, 1918 A, pp. 8-10, Halian- 

 thus, Kwiet. Halianthella , Kwiet, ? Hal cam - 

 pell a, Andres. 



