WILLIAMS: CRABS OF THE GENUS CALLINECTES 



segment nearly parallel sided but somewhat 

 broadened proximally. Mature female abdomen 

 and telson reaching same level as in male, length 

 slightly exceeding width (1.05 times); sixth seg- 

 ment longer than fifth. First gonopods of male 

 (Figures 18a, 20a) short, reaching about mid- 

 length of sternite VII, approximating each other 

 or occasionally overlapping at level of sharp distal 

 curve, distal portion abruptly curved laterad, ta- 

 pered to a rather sharp point, twisted one-fourth 

 turn on axis and, except for membranous spout- 

 like tip, armed with minute scattered retrogres- 

 sive spinules tending to arrangement in rows, a 

 few spinules proximal to flexure. Gonopores of 

 female (Figure 22b) ovate with apex on long axis 

 directed anteromesad, aperture of each with mar- 

 gin irregularly rounded and sinuous except on 

 mesial side where it slopes from surface laterad 

 under superior anterior border. 



Size of carapace in mm. — Largest male: lengt* 

 67, width at base of lateral spines 118, including 

 lateral spines 142. Largest female: length 49, 

 width at base of lateral spines 82, including lat- 

 eral spines 95. Mature size of females varies con- 

 siderably, the smallest examined having a 

 carapace length of 33 and width including lateral 

 spines of 70. Summary of selected measurements 

 is given in Tables 1 and 2. 



Color. — Carapace brown with areas of bluish 

 black. Chelae brown above; fingers dark on exter- 

 nal face except for tips and proximal portion, in- 

 ternal face dark in distal two-thirds; dark color of 

 fingers retained in preservation (in part from 

 Rathbun, 1930, and pers. commun. from Charles 

 A. Johnson). Milne Edwards and Bouvier (1900) 

 gave essentially the same impression, charac- 

 terizing the entire carapace, abdomen, external 

 face of chelipeds, posterior legs, some areas of the 

 walking legs with their marginal hairs as 

 greenish brown and other parts of the appendages 

 as a beautiful blue, but there is some confusion 

 here because the colored plate accompanying this 

 description (Plate 4, Figure 5) represents C. 

 sapidus. Rossignol (1957) described the carapace 

 as marbled, and recently preserved material in 

 alcohol sometimes does give an impression of mot- 

 tled gray and white on the carapace. 



Variation. — The carapace in C. marginatus 

 shows a number of individual variations. The 

 small anterolateral teeth generally trend forward, 



but there is enough individual departure from this 

 pattern to cause confusion. Teeth in the mesial 

 part of the row trend forward more than those in 

 the lateral part, the first three often being rounded 

 while the last four are pointed. Small anterolat- 

 eral teeth on syntype females in MNHNP do not 

 definitely trend forward, and those on the syntype 

 of C. larvatus (MCZ 5155) are well separated, with 

 apices directed outward rather than hooked for- 

 ward. There are differences, too, in width of the 

 anterolateral teeth, a suggestion of narrower 

 teeth in Brazil than in Florida, and broad teeth on 

 some African material. Occasionally there is some 

 iridescence along the anterolateral border, and 

 often hairiness along the lower anterolateral bor- 

 der. 



The inner orbital fissures are usually tightly 

 closed, sometimes with a slight notch on the orbit- 

 al border, but open in some African and Dutch 

 West Indies (Aruba) material. 



The anterolateral slopes have an arching con- 

 cavity proximal to the bases of the anterolateral 

 teeth and extending transversely behind the or- 

 bitofrontal region that is more pronounced than 

 in other species of the genus. This is especially 

 evident in mature females. The abdomen of imma- 

 ture males is flush with the sternum and rela- 

 tively wider than in adults in which it is somewhat 

 recessed. Among mature males, calcification is 

 weak in the articulation between the fifth and 

 sixth abdominal segments allowing definite 

 flexure in this joint, but transverse ridges ("stops") 

 on external exposed edges of the joint prevent 

 doubling backward. The calcification pattern is 

 well demonstrated in two mature males in USNM 

 4172 from Dominican Republic. Abdominal seg- 

 ment 6 is constricted at mid-length in some males. 

 The abdomen of adult females resembles that of 

 C ornatus. 



Sexual differences include a more tumid ap- 

 pearing body among females than males, an effect 

 resulting partly from less produced lateral spines, 

 as well as granulations on the carapace that are 

 relatively more prominent than on males. 

 Granules on the carapace sometimes are very 

 coarse in front of the epibranchial line, but seldom 

 as coarse behind as in front of this line. Incon- 

 spicuous spination on the male first gonopods in 

 specimens from the Canal Zone of Panama, Hon- 

 duras, Colombia, and Venezuela is not so strong 

 nor dense as that in males from Florida where 

 there is a suggestion that the scattered spines are 

 in rows proximal to the distal bend; spination 



725 



