August, 1999 
SCAMIT Newsletter 
Vol. 18, No. 4 
The Astropecten armatus pictured was a 
brilliant red, a color form we don’t see here in 
Southern California. It also had a very different 
structure than our local A. armatus , appearing 
somewhat less robust, and bearing a very 
different arrangement of the lateral arm spines. 
In local specimens these are large, flattened, 
largest at the base of the ray, and overlapping 
in the interambulacra. In the illustrated 
Galapagan specimen they are longest about 1/3 
of the way out the arm, are smaller and non¬ 
overlapping at the base of the ray, and do not 
appear flattened. The distal lateral arm spines 
are much longer in the illustrated individual 
than those seen in California specimens. No 
mention is made of the prominent spines of the 
interambulacral superomarginal plates in the 
text, and the photo is not large enough to 
demonstrate either presence or absence of such 
spines. 
The adjacent photo of Luidia folio lata looks 
much like Southern California Bight 
specimens, but seemed to show arms broader 
for their length, longer lateral arm spines, and 
an absence of the scattered individual white 
paxillae which are characteristic of the species 
in our area. 
It was finally time to start actually looking at 
specimens and mollusks were first up. Kelvin 
Barwick (CSDMWWD) brought an interesting 
and beautiful little opisthobranch from a 
Catalina Island station. After much 
examination it was determined that the animal 
belonged to the genus Akera. The genus has 
not hitherto been reported from the Eastern 
Pacific, and is almost certainly a new species. 
Two species are known from the tropical West 
Atlantic, several others from the western Indo- 
Pacific, and specimens of the genus were taken 
from the Pacific coast of Nicaragua in 1973. 
Their identity was never investigated, but they 
differed from the present specimen in being 
larger, and proportionately longer. The genus is 
the sole member of the family Akeratidae, and 
is related to the sea-hares. There are only a few 
species world-wide. 
A cephalaspid brought by Kelvin turned out to 
be a small Aglaja which was left as Aglaja sp. 
due to its small size. Another specimen which 
Megan Lilly (CSDMWWD) had examined was 
represented by only a shell. The animal had 
totally dissolved in the bleach used to remove 
the shell and gizzard plates. No gizzard plates 
were found, and the remaining minute shell 
had a strengthening rib running along the 
sweep of the anterior margin. It was 
reminiscent of a very small notaspid shell, 
rather than a philinid or aglajid cephalaspid. 
The absence of gizzard plates also matches 
with a non-cephalaspid. In the absence of the 
animal this was left at Opisthobranchia. 
A few small bivalves were then brought forth 
and turned out to be Diplodonta sericata and 
Rochefortia coani. Megan Lilly 
(CSDMWWD) brought two small clams she 
believed to be the Thyasiridae sp LA 1 
examined at an earlier meeting. It was 
confirmed that these were indeed the same 
animals. They were the cover illustration on the 
April NL [Vol. 17 No. 12]. These specimens 
were also from the Channel Islands (B ‘98 
Station 2523) and were taken at a depth of 
106m. 
The differences between the gastropod genera 
Astyris and Alia were reviewed as small 
specimens of both were examined. The 
lamellae in the periostracum of Astyris 
aurantiaca were easily viewed once Don 
positioned the animal properly. These were 
very thin and transparent on the juvenile 
examined, and were not easy to see. The 
paucispiral protoconch of Astyris spp. was also 
present, but not well marked. The tiny Alia 
examined was too small for specific 
determination, but looked like it might well be 
an A. carinata juvenile. 
After lunch echinoderms were next on the 
agenda as we had Nancy Carder visiting us 
specifically for the purpose of examining this 
group. Kathy Langan (CSDMWWD) brought 
some holothuroids discovered at the Channel 
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