November, 1999 
SCAMIT Newsletter 
Vol. 18, No.7 
the specimen - including the comprehensive 
keys to Japanese Caprella provided in Arimoto 
(1976), but to no avail. It was left at Caprella 
sp F of Paquette. 
Moving along to Leptostraca, several 
specimens of Nebalia sp were brought by 
Carol. The specimens were collected from 
Long Beach harbor intertidal and subtidal 
stations which were full of detritus. The 
specimens seemed to be part of the Nebalia 
pugetensis species complex, but they were 
distinguished by a broad, flat rostrum (very 
spatulate) and a very short ocular scale above 
the eye which extended 1/2 to 2/3 the length of 
the ocular peduncle (i.e., not reaching the eye 
proper). Specimens of Nebalia pugetensis 
complex typically have an elongate, tapering 
rostrum, which is much more triangular and 
dorsally arched in cross-section, and an ocular 
scale that extends the length of the eye 
peduncle to the eye proper. Carol volunteered 
to produce a SCAMIT voucher sheet on the 
animal. 
Tanaids were briefly reviewed during the 
examination of Synaptotanais notabilis 
recorded by CSD in the Bight’98 samples from 
San Diego and Mission Bay. We confirmed 
that these specimens were indeed S. notabilis 
and different from what Tony and Carol have 
been calling Zeuxo normani. 
Greg Williams and Janelle West from PERL 
(Pacific Estuarine Research Lab) brought 
specimens of Peneus calif orniensis (shrimp) 
for confirmation. Their ID was confirmed by 
Don. 
They also brought a Corophium sp (corophioid 
amphipod) which was identified as 
Monocorophium uenoi by Carol. 
Next, a Tethygeneia opata (eusirid amphipod) 
was identified using Carol’s key passed out 
earlier in the meeting. This estuarine species is 
seldom seen outside bays, but is listed in Ed. 3. 
It is easily separable from all other 
pontogeneoids found locally by the long 
triangular ventral lobe of the second gnathopod 
carpus. And finally, an Oxyurostylispacifica 
(Cumacea) was identified by Dean. He had 
recently compared a number of specimens of 
this taxon, and found it variable in the texture 
of the carapace. The examined specimens did 
not conform to the type description in that 
respect, and would have been suspect if Dean 
had not recently documented the variability. 
At this point the molluscs demanded the floor 
and staged a bloodless coup. Megan Lilly 
(CSDMWWD) had been working on B’98 
Station 2423 taken in Mission Bay (3.4 m) 
which was full of unusual molluscs. First up 
was a clam which turned out to be none other 
than Diplodonta orbellus, identified by Don 
Cadien. The animal was large (13 mm) for us 
and had nestled against a hard object and was 
slightly “tweaked”. 
Juvenile clams were up next. There were two 
Kellia sub orbicularis , and a small and strange 
looking Lyonsiidae (could get no further with 
the ID). Based on the strength of the radial 
incised lines on the valves this could represent 
a juvenile Entodesma rather than Lyonsia. Our 
current SCAMIT practice is not to identify 
specimens below 6mm to genus, so we left this 
one alone. Kelvin stated that he had perhaps 
made some headway in definitively separating 
small lyonsiids to at least genus, but his results 
are still preliminary. He will keep us informed. 
Several small gastropods were examined next. 
A very small Lithopoma undosum was 
identified by Don. This species has been 
transferred from Lithopoma to Megastraea in 
Turgeon et al (1998). The “stumper of the day” 
were two columbellids which were left at 
Columbellidae for the time being as they were 
not recognized by any of the members present. 
They seemed to be Mitrella or Astyris, but had 
shell patterns strongly reminiscent of an 
Anachis species from the Gulf of California. 
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