234 
BULLETIN OF THE BUREAU OF FISHERIES. 
III. Antipatharia. — Colonial zoantharia, usually with a hollow, branching skeleton of homy 
nature. So far as known, no representatives of this order occur in the region, which obviates the 
necessity for further account of it in this report. 
SYNOPSIS OF TRIBES OF ACTINIARIA. 
EDWARDSIAE R. Hertwig, 1882. 
Noncolonial Actiniaria with eight mesenteries, two pairs of which are directives; others unpaired, 
and their longitudinal muscles face the same direction; all mesenteries gonad bearing. Tentacles 
simple, few in number, usually more numerous than the mesenteries, varying from 12 to 36. Column 
more or less linear and cylindrical, often fluted along the lines of attached mesenteries. 
ZOANTHEAE R. Hertwig, 1882. 
Colonial Actiniaria, wdth numerous mesenteries of two sorts, namely, small, incomplete, and devoid 
of gonads; large, complete, and gonad bearing. A single oesophageal groove. Outer surface of body 
usually incmsted with a coating of sand or other foreign particles. Tentacles simple. 
CERIANTHEAE R. Hertwig, 1882. 
Actiniaria with numerous, unpaired mesenteries, except a single pair of directives, which are very 
diort and attached to the deep oesophageal groove. On either side of these will be found the much 
longer perfect mesenteries, which increase in size in regular order to the opposite (dorsal) side. Tenta- 
cles numerous and in two series — an outer principal and an inner accessory series — the circumoral tenta- 
cles. Body elongate, usually inclosed in a slimy flexible tube. Aboral end of body rounded and 
provided with a terminal pore. 
HEXACTINIAE R. Hertwig, 1882. 
Actiniaria witli six or more pairs of primary mesenteries. Other cycles arise in pairs, some of 
which may become perfect, others incomplete. The primary mesenteries are provided with retractor 
muscle fibers on their inner faces i. e., the muscles of each pair facing the intramesenterial space. 
There are usually two oesophageal grooves, with directive mesenteries, whose muscles face outward, or 
opposite the aspect of the other pairs. Body more or less smooth, often with longitudinal furrows, and 
in certain cases with wartlike nodular processes, verucae. Tentacles usually numerous and of various 
characters. 
The above tribal characteristics have been variously compilea from those given by Hertwig, McMur- 
rich, Haddon, Duerden, and Gosse, and to a less extent from Andres, Verrill, and others. 
FAMILIES OF HEXACTINI.E. 
ILYANTHlDdi Gosse (in part), 1858. 
Body usually elongate, cylindrical, aboral end rounded and with somewhat constricted, bulblike 
physa, but devoid of definite pedal disk. Tentacles simple and relatively few in number, or in some 
cases numerous; sphincter weak. 
There is considerable uncertainty as to the constitution of this family, some authorities even exclud- 
ing it altogether. Gosse, who established it, included under it the Edwardsise as well as the Ceriantheas. 
Hertwig considers the family as intermediate between the Edwardsiae and true Hexactiniae, and so 
ranks them in his system. (Op. cit., p. 92.) 
ANTHE 1 D.F Gosse (in part), 1858. 
Hexactiniae with well-developed pedal disk, often capable of expansion and inflation as a pneumato- 
phore. (Cf. Gosse, Actinologea Britannica, p. 149.) Column generally smooth, sometimes with verucae; 
tentacles long, very flexible, and disposed chiefly about the margin of the disk; mesenteries numerous; 
sphincter muscle very weak, rendering difficult any considerable contraction of disk or tentacles. 
