CLASSIFICATION OF ACTINIARIA 253 



perfect mesentery, but if so, whether it lias a retractor is 

 uncertain, and it is probably asymmetrical, not placed as in 

 Scytophorus. But only more and better material can 

 clear it up. H. arenaria I have left in the genus on the 

 assumption that it has a mesogloeal sphincter, but that remains 

 to be proved. 



Halcampoides, Dan., 1887. 



Bee Appellof, 1896, p. 8, and the references given under 

 Halcampa. Fenja, Dan. Aegir, Dan. Halcam- 

 pomorphe, Carlgr. Halcampa as used by Kwiet- 

 niewski. Halcampella as used by Hertwig. ?Hal- 

 campella, Andres. 



Halcampidae typically more or less worm-like, not necessarily with 

 a clear distinction into scapus, capitulmn, and physa. Cinclidea may 

 occur in the physa. Naked or incrusted. Tentacles twelve or more, 

 can be retractile, and with the tentacular longitudinal muscle ectodermal. 

 No mesogloeal sphincter, but there may be a slight eudodermal one. 

 .Six pairs of macrocnemes. Microcnemes present or not. 



Species: 

 H. abyss or um, Dan., 1887. 

 H. clavus, Q. and G., 1833, p. 150. (See Hertwig, 1882, p. 02 ; 



Pax, 1912, p. 310 ; Appellof, 1896. pp. 3, 13, &c. ; and Haddon, 



1889, p. 336.) 

 H. maxima, Hertw., 1888, p. 29. (See Wassilielf, 1908.) 

 H. kerguelensis, Hertw., 1888, p. 28. 

 H. purpurea, Studer., 1878, p. 545. (See Kwietniewski, 1896.) 



And probably others. 



H. mi nut a, Wass., seems to be more like a Haloclava 

 than a Halcampid. It is possible that of the species listed some 

 may be synonyms of others — it has been suggested that 

 H. clavus is the same as H. purpurea and H. abys- 

 s o r u m . Halcampella e n d r o m i t a t a , Andres, and others, 

 cannot yet be definitely allocated. In Wassilieff's description 

 of H. maxima there are some remarks which suggest 

 that he had some form other than a Halcampoides to 

 deal with ; but the}' may be due to a couple of critical 

 misprints. 



