Harris: Synopsis of genera and species 
189 
Key to the genera of Porcellidiidae 
The following key to the above genera is based on features that can usually be seen on whole animals 
in dorsal and ventral view except for the denticles on the male antennule which require the antennule to 
be fully extended. The shape and setation of the female caudal ramus are easily seen and can be used to 
identify species and genera. The range in shape and setation of the female caudal ramus is extensive, but 
not easy to define in words. Figure 12 shows diagrammatically the basic shapes referred to in the key. 
Multiple characters are given for each genus in the key, but confirmation of identity should be made 
by reference to Table 1 and the original descriptions of genera. 
1 Body egg-shape (ovoid). Females carrying eggs may have one 
or more spermatophores attached to P5s. Female caudal ramus 
trapezoid (Fig. 12A, B), T2 always present, T3 may be present 
or absent. Male antennule 5 segment 4 with large denticulate 
pad (never brush-pad). Porcelloides 
Body outline oval or elliptical. Females carrying eggs never have 
spermatophore attached (lost before egg laying starts). Female 
caudal ramus trapezoid, T2 and T3 always absent (Fig. 12C). 
Male antennule 5 segment 4 with brush-pad. (Fig. 12Q) . Kensakia 
Body outline oval or elliptical. Females carrying eggs never 
have spermatophore attached (lost before egg laying starts). 
Female caudal ramus rectangular, pentagonal or rhomboid. 
Male antennule segment 4 denticles variable in shape and 
number but never a brush-pad. 2 
2 Hyaline membrane with sensilla on ventral surface of cephalo- 
some, false cuticular border to cephalosome. Ducts of marginal 
glands open on ventral surface of cephalosome. Tectacingulum 
- Hyaline membrane with sensilla forms lateral border of 
cephalosome. Ducts of marginal glands open on dorsal surface of 
cephalosome. 3 
3 Coxal lobes of maxillipeds wide apart .4 
- Coxal lobes of maxillipeds touch in midline. 5 
4 T1 and y not deeply recessed at lateral corner of female caudal 
ramus, setae T1-T4 slender, T2 and T3 very close together. 
Terminal pair of setae on P3 and P4 endopod long, straight 
spinous (not plumose). No massive dorsal cuticular honeycomb. Dilatatiocauda 
T1 and y setae deeply recessed at lateral corner of female caudal 
ramus, T1 slender, T2, T3 and T4 large, pinnate, equally spaced. 
Massive cuticular honey-comb on back. Cereudorsum 
5 Female caudal ramus rectangular, setae T1 and y not recessed, 
Tl, T2, T3 and T4 large, pinnately clavate (Fig. 12D, R), equally 
spaced across posterior edge. Lateral ridges (rugosities) on 
anterior lobe of female genital double-somite. Clavigofera 
- Setae T1-T4 on female caudal ramus never pinnately clavate 
or equally spaced across posterior edge. No rugosities on 
female genital double-somite. Caudal rami may be rectangular, 
pentagonal or rhomboid . 6 
6 Female caudal ramus rectangular, may widen posteriorly, Tl 
and y setae may or may not be recessed at lateral corner, T2, T3 
and T4 attached to posterior edge, (Fig. 12E, F, G, H) . 7 
- Female caudal ramus pentagonal, medial corner 90°, lateral 
comer with Tl and y on sloping (bevelled) edge, T2 and T4 on 
straight posterior edge. (Fig. 121), T3 absent . 9 
