DIOGENES OF SINGAPORE AND THE MALAY PENINSULA 



47 



Chelipeds (Fig. 14) similar, subequal; dactyls and fixed fingers 

 with distinct hiatus; dorsal surfaces of palms relatively smooth 

 proximally with only few spinules, stronger spines distally; dorsal 

 surfaces of carpi each with irregular row of spinules becoming 

 strong spines at distal margin. Ambulatory legs with dactyls slightly 

 longer than propodi; propodi and carpi of second each with row of 

 spines on dorsal margins, partially obscured by long setae; propodi 

 of third unarmed, carpi each with spine on dorsodistal margin. 



Males lacking paired second pleopods; first paired, but consisting 

 of short, broad, uniramous 2-segmented appendages. Telson with 

 posterior lobes nearly symmetrical; terminal margins rounded, armed 

 with 5 or 6 spines. 



Redescription. Shield (Fig. 14) subtriangular, considerably 

 longer than broad, with numerous small spinules, spinulose tuber- 

 cles and tufts of plumose setae on dorsal surface, particularly 

 laterally. Rostrum broadly triangular, with very small terminal 

 spinule, not produced to level of terminal spinules of obtusely 

 triangular lateral projections. Branchiostegite with 4 or 5 slender 

 acute spines on dorsodistal margin partially to entirely obscured by 

 long setae. 



Ocular peduncles long and slender, slightly overreaching 

 antennular peduncles and approximately 0.50 longer than antennal 

 peduncles, dorsomesial surface with row of long setae; corneae 

 small, not dilated. Ocular acicles elongate and nearly rectangular, 

 dorsally flattened, with large tuberculate terminal spine and smaller 

 accessory spine laterally, with several long plumose setae distally. 

 Subquadrate calcified lobe (with 4 subacute spinules anteriorly in 

 holotype) seemingly articulated with interocular lobes. 



Antennular peduncles not reaching to bases of corneae; ultimate 

 and penultimate segments unarmed; basal segment with very strong 

 curved spine on dorsolateral distal margin, smaller spine on 

 ventrodistal margin. 



Antennal peduncles with supernumerary segmentation; reaching 

 only to about distal third of ocular peduncles; fifth, fourth and third 

 segments each with strong ventrodistal spine and scattered long 

 setae, most abundant laterally; second segment with dorsolateral 

 distal angle produced, terminating in bifid spine, lateral margin with 

 row of long setae, dorsomesial distal angle with strong spine; first 

 segment unarmed but with long setae laterally. Antennal acicle long, 

 reaching nearly to mid-length of ultimate peduncular segment, 

 broad and dorsally flattened, lateral margins each with 2 or 3 strong 

 spines and row of very long plumose setae, mesial margins each also 

 with 2 or 3 strong spines and row of plumose setae sufficiently long 

 to form a setal net above antennules, terminating in bifid spine. 

 Antennal flagellum short, not reaching beyond proximal margins of 

 chelipeds; each article with 1 or 2 long and 1 or 2 short setae. 



Chelipeds (Fig. 1 4) similar, subequal, right slightly larger (at least 

 in males). Dactyls approximately twice length of palms; dorsomesial 

 margins each with row of spines, dorsal and mesial surfaces with 

 fairly closely-spaced tuberculate spines and tufts of long setae; 

 cutting edges each with 1 or 2 large calcareous teeth proximally and 

 row of smaller calcareous teeth in distal 0.66, terminating in cor- 

 neous claw; dactyls and fixed fingers ventrally curved and with 

 distinct hiatus. Palms shorter than carpi, dorsomesial margins each 

 with row of 2 to 4 strong conical spines, dorsal surface relatively 

 smooth proximally with few spinules or spinulose tubercles, stronger 

 spines distally tending to form 1 or 2 irregular rows, and on weakly 

 delimited lateroproximal margin; fixed finger with dorsolateral 

 margin not clearly delimited, dorsal and lateral faces with closely- 

 spaced spinulose tubercles and spines; cutting edge with row of 

 calcareous teeth, strongest proximally; ventral surface of palm with 

 few scattered tubercles; all surfaces with tufts of long setae. Carpi 



trapezoidal in dorsal view; slightly less than 0.50 length of meri; 

 dorsomesial margins each with row of 4 strong conical spines, first 

 1-3 with very small spinule basally on mesial side, dorsolateral 

 margins each with irregular row of smaller spines, dorsal surface 

 with irregular row of spinules becoming strong spines at distal 

 margin; ventrolateral distal margins each with 1 or 2 small tubercles; 

 surfaces with long setae. Men each with longitudinal row of spinules 

 on dorsal margin in proximal 0.65, distally 1 transverse row of 

 prominent spines extending onto lateral and mesial faces dorsally 

 and second similar row on distal margin; ventromesial margin with 

 row of acute spines; ventrolateral margin with row of small spines in 

 distal half and short transverse rows of spinules proximally. Ischia 

 each with row of spinules on ventromesial margin and 1 small spine 

 at ventrolateral distal angle. 



Ambulatory legs with dactyls slightly longer than propodi; in 

 dorsal view slightly twisted, in lateral view curved ventrally in distal 

 halves; all surfaces, and particularly dorsal and ventral margins, with 

 rows of long setae. Propodi of second each with row of spines on 

 dorsal margins; carpi with single or double row of spines, all 

 partially to completely obscured by long setae; propodi of third (left 

 third broken at distal margin of ischium in holotype) unarmed but 

 with tufts of long setae on all surfaces, carpi only with spine at 

 dorsodistal margin or with 2 or 3 small spines in distal half, all at 

 least partially obscured by tufts of long setae. Meri of second each 

 with row of very small spinules and tufts of long setae on dorsal 

 margins, ventral margins each with row of spines and tufts of long 

 setae; third with few minute spinules on dorsal margin and tufts of 

 long setae, ventral margin with tufts of long setae. Ischia each with 

 1 or 2 spinules on dorsal margins, ventral margins each with row of 

 long setae and 1 small spine near distal margin. 



Males with paired gonopores; no paired second pleopods; first 

 paired but consisting of short, broad, uniramous 2- segmented 

 appendages positioned directly over coxae of fifth pereopods; un- 

 paired left pleopods 3 to 5 uniramous. Females with single left 

 gonopore; paired first pleopods modified as gonopods; very large 

 brood pouch. Telson with prominent, deep transverse suture; poste- 

 rior lobes nearly symmetrical, terminal margins rounded, each 

 armed with 4 to 6 spines, some corneous-tipped, and few moderately 

 long setae. 



Colour. Not reported. 



Distribution. Oman; Maldives; Red and Arabian Seas; Malay- 

 sia; Philippines. 



Remarks. Henderson ( 1 888) described the species from a single 

 male; however, he made no comment on any of the abdominal 

 appendages. Although Paguristes hians is a very distinctive species 

 that possesses characters unique among species of Paguristes, only 

 the remarks by Haig and Ball (1988) called attention to any of these. 

 These authors appear to have been the first to document that males 

 lacked the paired second pleopods typical of species of Paguristes; 

 they also pointed out the presence of a single left gonopore in the 

 female. It may be that these abnormalities were recognized by Grant 

 and McCulloch (1906) and McCulloch (1913) who incorrectly 

 identified atypical Paguristes specimens from Mast Head Island, 

 Queensland, Australia, as P. hians. Haig (in Haig and Ball, 1988) 

 showed that at least some of the Mast Head Island specimens 

 actually were referable to P. monoporus Morgan. As described by 

 Morgan (1987a) this is another rather bizarre species of Paguristes 

 in which male first and second pleopods are reduced and restricted 

 to the right side of the abdomen; males possess only a single right 

 gonopore and females have only a single left. 



While the characters described above for P. hians set this species 



