
46 RECORDS OF THE S.A. MUSEUM 
First thoracic segment fused with the cephalon; urosome 4- or 5-segmented 
in the female; 5-sezgmented in the male. First antenna 5- to 7-segmented. Second 
antenna usually armed only with setae. Labrum short and broad, fringed with 
fine spinules. Mandible reduced, without a palp and armed always with one ter- 
minal claw with or without accessory pieces which are never more than three in 
number. Maxillule bilobed, the smaller inner lobe armed with spines, the outer 
lobe with setae only or reduced to a single lobe armed only with setae. Maxilla 
short and stout, 2-sezmented, the proximal segment armed with simple spines, the 
distal segment with two strong claw-like spines. Maxillipeds reduced and scarcely 
prehensile in the female but well-developed and strongly prehensile in the male. 
Swimming legs usually of normal structure, though showing a peculiar modifica- 
tion of the first pair in Clausidium. Fifth legs lamellar, one- to three-segmented. 
The following genera are included : 
Hemicycuops Boeck. 
Hemicyclops Boeck, 1873. Saphirella Wolfenden, 1905. 
nee Hemicyclops Claus, 1893. Hemicyclops Sars, 1917. 
Platycheiron T. and A. Scott, 1892. Saphirella Sewell, 1924. 
Saphirella T. Seott, 1894. Hemicyclops Light and Hartman, 1937. 
CLAUSIDIUM Kossmann, 
Binoculus Say, 1818. Clausidium Embleton, 1901. 
Hersilia Philippi, 1839. Clausidium Light and Hartman, 1937. 
Clausidium Kossmann, 1874. 
HeERSILIODES Canu. 
Hersiliodes Canu, 1888. Hersiliodes Thompson and Scott, 1903 (pro 
Hersiliodes Bourne, 1890. parte). 
H. dubia Thompson and Scott (1903) is clearly a Hippomolgus, the only male so far described 
for this genus. 
GIARDELLA Canu. 
Giardella Canu, 1888. Giardella A. Scott, 1906. 
GorpELIA Embleton. 
Goidelia Embleton, 1901. 
Hippomo.eus Sars. 
Hersiliodes Thompson and Scott, 1903 Hippomolgus Sars, 1917. 
(pro parte). 
KEY To THE GENERA. 
1. First legs modified into sucking organs .. on Clausidium Kossmann 1874. 
First legs normally developed . ; ne o 2, 
2. Second antenna prehensile, armed with eben fifth ibe three- eaten hah 
Goidelia Embleton 1901. 
Second antenna non-prehensile, armed only with setae; fifth legs one- or two-segmented .. 3. 
3. Fifth leg one-segmented oe < $0 whe iol veh, 
Fifth leg two-segmented b? os ap a oe Peas 
4. First antenna short and compact fe 8 ..  Hippomolgus Sars 1917. 
First antenna long and slender e. is Pa Hersiliodes Canu 1888. 
5. Mandible armed with one claw and two hooks , Giardella Canu 1888. 
Mandible armed with one claw, one toothed plate, and two setae Hemicyclops Boeck 1873. 
Genus Hemicycuors Boeck. 
Sars, 1917, p. 145; Light and Hartman, 1937. 
A key to the species of this genus has been given by Light and Hartman, who 
have discussed the genus and give reasons for excluding the two species Hersiliodes 
