IDENTITY OF SOME MARINE ANNELIDS—HARTMAN 133 
Genus MEGALOMMA Johansson 
MEGALOMMA CIRCUMSPECTUM (Moore) 
Branchiomma circumspectum Moore, 1923, p. 239 (U.S.N.M. No. 17021; off Santa 
Rosa Island, Calif., in 38-45 fathoms). 
The collar membrane has high dorsal lappets, covering the peri- 
stomium; between its lobes and the lateral lobes there is a slight 
emargination and a deep cavity that extends down nearly through 
the first and second setigers, like a pocket; lateral lobes are slightly 
oblique and continued ventrally without incision, in a pair of long 
triangular flaps. Most radioles have small, more or less spherical, 
compound eyes at their tips. 
M. circumspectum has been identified with I. mushaensis (Gravier) 
from the Red Sea (Monro, 1933, p. 1078), but I believe there are 
differences in the collars of the two that cannot be considered as mere 
variations of the same species. They are herein considered to be 
distinct. 
Genus HYPSICOMUS Grube 
HYPSICOMUS CIRCUMSPICIENS Ehlers 
Hypsicomus circumspiciens EHLERS, 1887, p. 271. 
Hypsicomus purpureus TREADWELL, 1924, p. 20 (U.S.N.M. No. 20325; Antigua). 
The single type specimen of H. purpureus originates from the 
Pillars of Hercules, Antigua. The eye spots, originally described, 
are now faded out. Thoracic spatulate setae are broad, without (or 
with only a tiny) mucro. This specimen agrees well with the 
description of H. circwmspiciens Ehlers, except that the tentacular 
crown is shorter in the first; however, it had been fixed outside the 
tube, permitting greater contraction. 
H. circumspiciens is known from the West Indian region through 
other records, including Sabella alba Treadwell (1917, p. 266) and 
Parasabella sulfurea Treadwell (1917, p. 267). Johansson (1927, p. 
139) has discussed the synonymy. 
HYPSICOMUS species 
Potamilia californica TREADWELL, 1906, p. 1178 (U.S.N.M. No. 5222; vicinity of 
Monterey Bay, Calif.). 
The single type specimen bears the label “vicinity of Monterey 
Bay. Alb. Sta. 4551. 56-46 fms.” The setal fascicle in the collar is 
an elongate series; it is an example of Hypstcomus Grube. 
Another collection, labeled “Potamilla californica” (U.S.N.M. No. 
17119) from Monterey Bay, Calif., Albatross station 4496, May 19, 
1904, in 10 fathoms, contains a single, large specimen of Demonax 
media (Bush). Still another collection (U.S.N.M. No. 17120) from 
Monterey Bay, Albatross station 4463, May 18, 1904, in 111 fathoms, 
contains specimens of Pseudopotamilla intermedia Moore. 
