NO. 3599 PORTUNID CRABS — STEPHENSON AND REES 5 



Measurements made upon the original 16 narrower specimens 

 and upon randomly selected specimens from the remainder showed 

 that the differences in proportions were not primarily due to dif- 

 ferent lengths of the last anterolateral teeth; thereafter only lengths 

 and breadths of carapaces were measured. L/B ratios were variable 

 and were not obviously related to the size or sex of the specimens. 

 Data on 104 specimens are given as a frequency distribution diagram 

 on figure 1. The specimens include the 16 narrow individuals, 

 randomly chosen small individuals from several collections, and the 

 larger individuals from several collections. Because the figure 

 shows only a slight hint of bimodality, the narrower specunens do 

 not merit separation from the remainder. 



Alcock's var. pusilla appears to be within the range of variation 

 of the one taxonomic entity and, following Leene's suggestion, is 

 added to the synonymy of the present species. On the other hand, 

 Leene's (1938) var. omanensis merits specific status, although there 

 are problems of synonymy with C. smithii Mc Leay 1838. Meanwhile 

 Leene's var. longicollis clearly has specific status (see below). 



Charybdis longicollis Leene 



Charybdis hopliles Balss, 1924, p. 2 [specimens from Ras Abu Somer]. 



Charybdis {Goniohellenus) hopHtes var. lonyicoUis Leene, 1938, pp. 107-110, figs. 



59, 60a-c.— Stephensen, 1945, pp. 118-9, figs. 24 F-G, 25.— Crosnier, 1962, 



pp. 86-7, figs. 140, 147, 148, pi. 7 (fig. 2). 

 Charybdis (Goniohellenus) longicollis Leene. — Holthuis, 1961, pp. 47-50, figs. 14, 



15. 

 Charybdis longicollis Leene. — Lewinsohn and Holthuis, 1964, pp. 57-8. 

 Not Charybdis hopliles Wood-Mason, 1877, p. 422. 



Material examined. — 1 male (40.5 mm), Sta. No. 258A. 3 

 males (24.5-28 mm), 1 female (21 mm), Sta. No. 266A. 1 ovig. 

 female (29 mm), Sta. No. 268A. 



All trawled, depths from 30 to 368 m, bottoms all muddy. 



Remarks. — Charybdis hoplites and C. longicollis resemble each 

 other in possessing (1) relatively short and slightly curved antero- 

 lateral borders, (2) last anterolateral teeth of moderate length and 

 directed laterally or sHghtly forwards, (3) anterolateral teeth gen- 

 erally somewhat square-cut, but with forwardly directed anterior 

 spines, (4) mesobranchial area of carapace swollen, (5) no longitudinal 

 Une of granules on carapace running from mesogastric to metagastric 

 region, (6) metagastric region of carapace with short granular ridges, 

 (7) median frontal lobes protruding beyond submedians and narrowly 

 rounded. 



Charybdis longicollis is distinguished from C. hoplites by having 

 (1) cardiac and mesobranchial areas of carapace with ridgelike 

 elevations, as against granular patches; (2) sides of antepenultimate 



