6 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 120 
The 6 pairs of macrocnemes of first cycle have large restricted 
retractors (fig. 2b) running throughout their length, while second 
cycle has only slightly smaller restricted retractors. Directive re- 
tractors tend to be circumscript. There is a moderately well-developed 
parietal musculature on macrocnemes, while microcnemes (fig. 26) 
consist only of parietal muscles, there being no mesenterial sheet. 
A trifid mesenterial filament and acontium are present on each mac- 
rocneme, but were not observed on any microcneme. 
Cnidom (spirocysts, atrichs, basitrichs, and microbasic amastigo- 
phores) : 
tentacles 
microns 
spirocysts 17-22 3.0—4.0 
basitrichs 19-27 X 3.0-4.0 
basitrichs 14-16 X 2.5-3.0 
scapus 
basitrichs 18-26 X 3.0-3.5 
basitrichs 9-14 2.0-2.5 
atrichs (rare) 8-10 3.0 
actinopharynz 
basitrichs 26-34 X 5.0-6.0 
basitrichs (rare) 18-20 4.0-5.0 
microbasic amastigophores 16-20 X 5.0-6.0 
filaments 
basitrichs 24-29 X 3.0-4.0 
basitrichs (rare) 12-16 X 2.0-3.0 
microbasic amastigophores 14-18 X 4.5-6.0 
acontia 
basitrichs 20-29 X 2.5-3.0 
basitrichs (rare) 16-18 X 2.0—-2.5 
microbasic amastigophores 33-42 X 5.0-7.0 
Type locality: Bay Farm Island, Alameda Co., Calif. 
Holotype: Deposited in the United States National Museum as 
no. 52592. 
Paratypes: Five additional specimens are deposited in the United 
States National Museum as nos. 52593 and 52594. 
Discussion 
The new species described herein is abundant in the intertidal zone 
of many parts of San Francisco Bay and also occurs in the estuary 
separating Alameda from Oakland, Calif. Flosmaris grandis is only 
the third species assigned to this genus, the others being the type 
species, I’. phellioides Stephenson, 1920, and F. bathamae Hand, 1961. 
F’. phellioides was described from a single specimen collected at Hulule 
Island, N. Male Atoll, Maldive Archipelago, and F. bathamae is 
known only from Otago Harbor in southern New Zealand. F. 
bathamae is a small species, the maximum length being about 2.5 cm., 
