1977] 
Moore — Larva of Rothrium sonorensis 
265 
row of ten setae, two setae laterally at the anterior margin and 
several other scattered lateral setae. Ninth tergite narrower than 
eighth, which is produced posteriorly in its central third in a nar- 
rowly rounded dark lobe that probably represents opercula for an 
osmeterium. Urogomphus one-segmented with a long seta at 
pointed apex. Pseudopod represented by a short narrow projec- 
tion at the apex of a small broad triangular organ, the entire struc- 
ture not more than half as long as the urogomphus, the cylindrical 
apical projection about one-third as wide as the urogomphus. 
One specimen taken in company with five adults at Mexico, 
Sonora, Tide Pool Beach, 29.49-112.40, 20 March 1974, V. Roth 
and W. Brown, collectors. Another specimen was taken by V. 
Roth at Mexico, Sonora, Punta Cirio, 29.50-112.39, 12-20 Janu- 
ary 1974, from intertidal rock crevice. 
Among the marine Bolitocharini the larva of Phytosus nigriven- 
tris Chevrolat was described by Fauvel (1862), that of Halmaeusa 
atriceps (Waterhouse) by Paulian (1949) (as Antarctophytosus ), 
those of Liparocephalus cordicollis LeConte and Diaulota densis- 
sima Casey by Saunders (128) and Chamberlin and Ferris (1929). 
These descriptions were reviewed by Moore (1956) who described 
the larvae of three more species of Diaulota and gave a key to the 
genera and the species of Diaulota. 
Key to the Known Larvae of the Genera of the 
Marine Bolitocharini 
1. Apex of ninth abdominal segment truncate . . Phytosus Curtis 
Apex of ninth abdominal segment produced in two appendages 
(urogomphi) 2 
2. Urogomphus not segmented 3 
Urogomphus segmented 4 
3. Antenna 3-segmented Liparocephalus Maklin 
Antenna 2-segmented Diaulota Casey 
4. Urogomphus one-segmented Rothium Moore & Legner 
Urogomphus 2-segmented Halmaeusa Kiesenwetter 
Literature Cited 
Chamberlin, J. S. and G. F. Ferris 
1929. On Liparocephalus and allied genera. Pan-Pac. Ent. 5: 137-143, 1 53— 
162. 
