DIOGENES OF SINGAPORE AND THE MALAY PENINSULA 



45 



Lanchester's specimen does more closely resemble Morgan and 

 Forest's ( 1991 : fig. lib) illustration of the syntype ofD.jousseaumei; 

 however, it falls well within the range of variation in acicular length 

 and armature seen in D. stenops. It is quite possible that D. stenops 

 and D. jousseautnei may coexist geographically while occupying 

 different microhabitats. With the exception of shell occupancy 

 (Murex is reported forD. stenops), little is known about the ecology 

 of either species. 



Another instance of geographic sympatry in species of the 

 Troglopagurus group has recently been documented. As previously 

 indicated, Diogenes stenops has been recorded from Singapore 

 (Rahayu and Forest, 1995), the type locality of D. jubatus Nobili, 

 1903. Although rarely reported and poorly known, the recent 

 redescription of D. jubatus by Lemaitre and Ng (1996) demonstrates 

 clearly the distinctiveness of the two species. 



Diogenes mixtus Lanchester, 1902 



(Figs 7f, 8f, 9i, 13a) 



Diogenes mixtus Lanchester, 1902:367, pi. 34, figs 2, 2a, 2b; Nobili, 

 1903:16; Alcock, 1905b: 165 (list). 



Material examined. Lectotype (herein selected). cf (SL = 6.88 

 mm), Pulau Bidan, Penang, Malay Peninsula; UMZC 1.10050. 

 Paralectotypes. 7cf, 149, 1 ovigerous 9 (SL = 4.15-7.53 mm), 

 Pulau Bidan, Penang, Malay Peninsula; UMZC 1.10050. 



Additional material. 1 9 (SL = 4.95 mm), Kuching, Malaysia; 

 BMNH 1928.12.1.283. 



Diagnosis. Shield (Fig. 7b) with anterior margin weakly denticu- 

 late over 0.75 total length; rostrum obtuse, not reaching level of 

 lateral projections. Rostriform process elongate, overreaching ocu- 

 lar acicles by approximately third own length, multidenticulate. 

 Branchiostegites unarmed. Ocular peduncles overreached by both 

 antennular and antennal peduncles; ocular acicles broadly triangu- 

 lar, with 1 or 2 prominent spines mesially, with row of smaller spines 

 extending entire terminal margin. Antennal acicle bifurcate; mesial 

 fork with 0-2 small spines on outer margin and 2-4 smaller spines 

 on inner margin; lateral fork reaching beyond distal margin of fourth 

 peduncular segment, 4 or 5 small spines on inner margin and 0-3 

 spinules on outer margin. 



Left cheliped (Fig. 13a) with outer face of palm armed with 

 double row of blunt spines extending from nearly proximal margin 

 almost to tip of fixed finger, with blunt spines scattered on fixed 

 finger and in somewhat irregular rows on ventral margin, midline of 

 palm with 2 irregular rows and tubercles dorsally ; upper margin with 

 2 rather widely-spaced rows of small spines; dactyl with similar 

 rows of spines; carpus with double row of somewhat blunt spines on 

 upper surface, distal margin of outer face with row of spines curving 

 proximally near ventral margin; merus with acute row of spines on 

 dorsal margin, ventrolateral margin with row of acute spines, 

 ventromesial margin with double row of somewhat blunted spines. 

 Dorsal surface of palm of right cheliped with scattered spines, 

 partially obscured by long setae, dorsomesial margin with row of 

 small spines; upper outer and distal margins of carpus each with 

 irregular row of acute spines. Ambulatory legs generally similar; 

 dactyls (Fig. 8f) longer than propodi, dorsal margins with small 

 spines becoming obsolete in distal half; propodi each with 2 rows of 

 spines on dorsal surface; carpi each with row of spines on dorsal 

 margin. 



Telson (Fig. 9i) with terminal margin minutely spinulose on right, 

 strongly spinose on left and approaching lateral angle, continued 

 onto lateral margin over approximately half length. 



Redescription. Shield (Fig. 7b) longer than broad, subovate to 

 subquadrate; anterior margin with row of closely-spaced small 

 tubercles or blunt spinules over 0.75 to entire width; rostrum obtuse 

 or broadly triangular, weakly produced, not reaching level of lateral 

 projections; lateral projections unarmed or with small to moderately 

 strong terminal blunt or acute spinule. Intercalary rostriform process 

 elongate, overreaching ocular acicles by 0.25-0.50 own length, 

 multidenticulate, with 3-7 lateral spines on each side of terminal 

 simple, bi- or trifid spine. Inner pterygostomial plate (cf. Pilgrim, 

 1973) with strong distal spine. Branchiostegites with upper margin 

 usually with row of closely-spaced small blunt or spinulose tuber- 

 cles partially obscured by tufts of long setae. 



Ocular peduncles, moderately slender, comeae not particularly 

 dilated; overreached by both antennular and antennal peduncles. 

 Ocular acicles broadly triangular, usually with 1 or 2 more promi- 

 nent spines mesially, with row of smaller spines or spinulose tubercles 

 extending entire terminal margin. 



Antennular peduncles overreaching ocular peduncles by 0.25 to 

 nearly entire length of ultimate segment; overreaching antennal 

 peduncles by 0.10-0.50 length of ultimate segment. Ultimate and 

 penultimate segments with scattered setae. Basal segment with row 

 of tiny spinules or tubercles on both distomesial and distolateral 

 margins. 



Antennal peduncles with numerous long setae on fifth segment, 

 particularly dorsally and ventrally. Fourth segment with scattered 

 stiff setae. Third segment with spinule at ventrodistal angle. Second 

 segment with dorsolateral distal angle produced as acute spine, 

 lateral margin with low protuberances or spinules and long setae; 

 dorsomesial margin with row of small spinules, dorsal surface with 

 scattered spinules. First segment with row of tiny tubercles or 

 spinules on dorsal, dorsolateral and ventrolateral distal margins, 

 ventrodistal angle with strong spine. Antennal acicle strongly bifur- 

 cate; mesial fork with acute or bifid termination, 0-2 small spines on 

 outer margin and 2-5 smaller spines on inner margin; lateral fork 

 reaching to or beyond distal margin of fourth peduncular segment, 

 terminating in acute simple or bifid spine, 4-14 small spines on inner 

 margin and 0^4 spinules on outer margin, dorsal surface usually 

 with scattered spinules. Antennal flagellum moderately long, usu- 

 ally reaching to or beyond tip of left chela; several proximal articles 

 usually with 1 or 2 short or moderately long stiff setae; setae of 

 articles in distal two-thirds much shorter. 



Left cheliped (Fig. 13a) with fingers opening nearly vertically; 

 cusp-like calcareous teeth on cutting edges of both dactyl and fixed 

 finger. Upper margin of dactyl armed with double row of small 

 spines and moderately dense, but relatively short setae; outer surface 

 with scattered small conical tubercles, row of tufts of stiff setae 

 adjacent to cutting edge; inner surface with scattered tufts of setae. 

 Palm with double row of subacute or acute spines on upper margin; 

 outer surface triangularly convex, with widely scattered conical, 

 often rather blunt spines on both lower half of palm and fixed finger, 

 2 irregular frequently rather widely-separated longitudinal rows of 

 slightly stronger spines in midline of palm and 1 shorter row in upper 

 half, row of blunt or subacute spines on lower margin, becoming 

 double row on fixed finger, lower and inner surfaces of palm 

 tuberculate. Carpus with double row of acute, subacute or blunt 

 spines on upper surface; outer face with numerous spines, strongest 

 in lower half, distal margin with row of small spines, lower margin 

 spinulose or spinose, inner face with weakly tuberculate or spinulose 

 distal margin, longitudinal row of spinulose protuberances or spines 

 and long setae near upper margin. Merus broadly triangular distally ; 

 acute row of spines on dorsal margin, diverging distally into mesial, 

 dorsal and lateral rows extending to or nearly to distal margins; 

 dorso- and laterodistal margins with continuous row of moderately 



