210 
PACIFIC SCIENCE, VoL XIX, April 1965 
atrichs 21.2-32.8 X 2 .4-4.4 g rare or absent, 
microbasic b-mastigophores 18.4-50.8 X 2.8- 
9.2 g scarce, spirocysts 14.4-26.8 X 1-8—5 .2 g 
common. Of peloton of microseptum, micro- 
basic b-mastigophores 18.4-30.0 X 4.4-7 .6 g 
very common. 
Pachycerianthus torreyi is clearly distin- 
guished from the two species described by Tor- 
rey and Kleeberger ( 1909) from southern Cali- 
fornia. The present species and P. aestuari dif- 
fer in that the latter possesses a siphonoglyph 
which does not reach the lips of the actino- 
pharynx and has four mesenteries commonly 
reaching the terminal pore. Other characters of 
P. aestuari which may differentiate it from P. 
torreyi are a tentacle number which never ex- 
ceeds 34, a single cycle of marginal tentacles, 
and a very broad siphonoglyph. 
Pachycerianthus johnsoni differs from P. tor- 
reyi in that the directive mesenteries do not 
extend beyond the siphonoglyph, as is the case 
in the present species. Other characters of P. 
johnsoni with possible diagnostic value are that 
gonads are frequently borne on the third order 
mesenteries, that the siphonoglyph is narrow, 
and that the Bi may be longer than the P 3 . 
Among approximately one hundred cerianthid 
specimens taken and examined from deeper 
water in Los Angeles Harbor, the type locality 
for P. johnsoni, no specimens of this species 
were found. It is probable that it is a shallow 
water species and that the mud-flat habitat 
where the two specimens were collected has 
been eliminated by harbor installations. 
The clarity with which the present species 
can be distinguished from the other species in- 
cluded in the genus depends, in good part, on 
the detail in which they have been described. 
We have seen that the type species, P. bene- 
deni, was very poorly described, but it is pos- 
sible to distinguish it since there is a regular 
diminution in the length of the metamesente- 
ries, i.e. M 3 is shorter than M 2 . Pachycerian- 
thus insignis, based on a single incomplete 
specimen from the Gulf of California, has sev- 
eral metamesenteries almost reaching the aboral 
pore, and a Po that is more than twice the 
length of Pi. 
Pachycerianthus torreyi is most similar to 
P. plicatus , an Indonesian species, differing 
only in the relative lengths of the M2 and M 3 
mesenteries. Pachycerianthus fmbriatus , from f 
the same area as P. plicatus, differs in the same 
character and possibly in the arrangement of 
the labial tentacles. Pachycerianthus bicyclus 
and P. solitarius differ from P. torreyi in the 
absence of craspedonemes of the trineme and 
in that several M mesenteries nearly reach the 
aboral pore. The latter character may also be 
used to distinguish P. monostichus, P. dohrni, 
and P. multiplicatus from the present species. 
Pachycerianthus maua differs by having the M 3 
mesentery shorter than the M 2 , and also by pos- 
sessing an unusual type of aboral craspedoneme. 
The name, torreyi , is in honor of Dr. H. B. 
Torrey, one of the earliest workers on cerian- 
tharian taxonomy in California. 
GLOSSARY 
As Torelli (1960:373) has pointed out, the 
terminology applied to the Ceriantharia has 
become exceedingly complicated through the 
multiplication of terms. In the following glos- 
sary the full definition of a structure has been 
placed with the presently accepted term and 
other terms have been referred to this defini- 
tion. English nomenclature or anglicised terms 
are used. Terms have been added from other 
languages where these are not direct transla- 
tions. The application of certain terms to re- 
lated groups of animals has been given when 
they are likely to cause confusion. 
1 (metamesentery) (Carlgren, 1912A368) — 
longest metamesentery in each quartette, i.e. 
metamesentery of the first order. 
1 (tentacle) (Carlgren, 1900:25-26; McMur- 
rich, 1910:17-18) — tentacle of innermost 
cycle of a crown. 
1 subscript ( metamesentery ) (Carlgren, 1924^: 
169-170) — belonging to first metamesente- 
rial quartette (q.v.). 
1 subscript (protomesentery) (Carlgren, 1912^: 
12) — belonging to first protomesenterial 
couple. 
1 superscript (Beneden, 1923:24-25) — clos- 
est structure to siphonoglyph in metasome 
(q. v.). 
Id superscript (Beneden, 1897:10-11) — first 
structure to right with reference to directive 
plane at the siphonoglyph. 
