Harris: Synopsis of genera and species 
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Table 1. A summary of characters used to define genera in the Porcellidiidae (§ autapomorphic character, t apomorphic 
character). * For types of coupling denticle arrangement see Harris (2014b, p. 162). Characters i to xxxiii are considered 
plesiomorphic. Alternative (apomorphic) characters, indicated within parentheses ( ), refer to other genera, see genera 
numbered 2-16 in this table. 
1 Porcellidium Claus, 1860 (type species P. viride ) [20 species] 
i Spermatophore elongate. (11). 
ii Normally deposited ventrally on the female’s genital double-somite. (11). 
iii Spermatophore ephemeral, shed before egg laying starts. (11). 
iv Female receives only one spermatophore during her life span. (11). 
v Female cephalosome semicircular, not truncated anteriorly. (5, 12, 15). 
vi Male cephalosome truncated anteriorly. (9, 13). 
vii Hyaline border to cephalosome. (3). 
viii Ducts of marginal glands open dorsal to hyaline border. (3). 
ix No honeycomb-like pattern of cuticular folds on cephalosome. (5, 10, 14). Dorsal organs absent. (14). 
x Male genital somite not fused to P5 baseoendopod and segment 4 of metasome. (12). 
xi Female genital double-somite posterior lobe broad, rounded. (2, 6, 7, 8, 12, 13, 14, 15). 
xii No striations (rugosity) on anterior lobe of female genital double-somite. (6). 
xiii Anterior and posterior lobes clearly indicated by notch or cleft. (7, 8, 12, 13, 15). 
xiv 50% or more of caudal furca enclosed in posterior arch of genital double-somite. 
xv Female caudal ramus rectangular, but T1 and y setae may be recessed at external comer. (2, 7, 8, 9, 11, 12, 13, 15, 16). 
xvi Terminal setae T1 to T4 always present on caudal ramus.(8, 9,11,12, 13, 15, 16). Setae never pinnate clavate, Fig. 12R. (6). 
xvii T2 and T3 very close together, never he parallel to posterior border. (2). 
xviii a and (1 setae on caudal ramus never very close together (i.e., not less than width of ramus). (10). 
xix No ridge plates on labrum. (10). 
xx No denticle or comb on segment 3 of male antennule; ventral process (blade or knob) may be present. (4, 7, 8, 9, 13). 
xxi Anterior process on segment 3 of male antennule with 8 and 8' setae that point forward, not laterally. (4, 10). 
xxii Segment 4 of male antennule has three coupling denticles (shape variable, but never a brush-pad). (2, 3, 4, 6, 8, 9, 12, 13, 14, 15). 
xxiii Endites on maxillule with three or four setae each. (5, 9, 16). 
xxiv Endopod of maxillule with six setae. (5, 9, 16). 
xxv Coxae of maxillipeds touch in mid-line. (10, 14). 
xxvi Fimbriate process always present on basis of maxilliped. (10, 14). 
xxvii Exopod segment 3 of P2, P3 and P4 with three external setae. (12). 
xxviii Terminal pair of setae on segment 3 of female P3 and P4 endopod plumose. (10). 
xxix Female P5 shorter than genital double-somite. (2, 5, 6, 7, 8, 9, 11, 13, 14, 15). 
xxx No ventral expansion of falciform ridge on female P5. (7). 
xxxi Male P5 trapezoid with six setae (one lateral, five terminal). (12). 
xxxii Animals dorsoventrally flattened, oval or elliptical in outline, 
xxxiii No notch at distal end of falciform ridge on female P5. (7, 8, 12). 
2 Acutiramus Harris & Robertson, 1994 [12 species] 
i Female P5s reach beyond genital double-somite and caudal rami to touch one another posteriorly. 
ii Female caudal ramus rhomboid (not rectangular). 
iii Setae Tl, T2 and T3 always present on male and female caudal ramus. 
iv T2 and T3 very close, may he parallel to posterior border. 
3 Tectacingulum Harris, 1994 [2 species] 
i Hyaline membrane on ventral side of cephalosome. § 
ii Marginal glands open on ventral side of cephalosome. § 
iii Large area of short peg-like setules on segment 1 of PI exopod. § 
iv False (cuticular) border to cephalosome. § 
4 Murramia Harris, 1994 [2 species] 
i Male antennule segment 3 8' absent from anterior process. § 
ii Unique arrangement of denticles on male antennule (type E*).§ 
5 Brevifrons Harris, 1994 [1 species] 
i Unique arrangement of denticles and setae on male antennule (unipinnate seta associated with sensory lobe on segment 4). § 
ii Maxillule formula for endite setae 2-2-1. § 
iii Maxillule with two setae on endopod. f 
iv Low honeycomb-like ridges on dorsal surface of cephalosome.f 
v Male and female cephalosome truncated anteriorly.] - 
6 Clavigofera Harris & Iwasaki, 1996b [5 species] 
i Anterior lobe of female genital double-somite with lateral band of ridged cuticle (rugosity). § 
ii Terminal setae Tl to T4 large, pinnately clavate.§ 
iii Seta Tl identical in size to T2, Tl to T4 evenly spaced across posterior border of caudal ramus.§ 
iv Setae Tl and y not recessed at lateral corner.f 
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