254 OCYPODE AFRICANA. 



without any terminal prolongation. Lateral surfaces of the 

 ceplialothorax smooth, pterygostomian regions convex and 

 coarsely granulated; suborbital margin granulated, with a 

 small incision near the middle, covered with some hairs 

 and making a nearly straight angle with the external or- 

 bital angle. External surface of the outer foot-jaws a little 

 granulated and hairy. Sternum punctate, first segment 

 (between the chelipedes) a little granular. Male abdomen 

 much narrower than that of Oeyp. cordimana , terminal 

 segment triangular as long as broad , second segment rather 

 somewhat longer than broad at the base, with the lateral 

 margins much arcuated outward, and therefore having a 

 very characteristic shape , both segments minutely punctate ; 

 third segment quadrangular, punctate, rather longer than 

 broad, with the lateral margins nearly straight; fourth 

 segment quadrangular, more than twice as broad as long, 

 a little granular, like also the three remaining basal seg- 

 ments, that have nearly the same shape as in Ocyp, cor- 

 dimana. 



Chelipedes very unequal in size, almost wholly agreeing 

 as regards their shape and structure with those of Oci/p. 

 cordimana Latr. Musical ridge extending from near the 

 granulated inferior margin till near the upper angle of 

 the articulation of the mobile finger , composed out of de- 

 licate transverse lines that become gradually narrower to- 

 wards the upper part of the ridge , but do not change into 

 tuberculcs, Internal surface of the large hand granulated; 

 under surface of the trochanters of both chelipedes armed 

 with a linear tubercle striated longitudinally, that serves as 

 a fiddlestick for the musical ridge, that of the larger tro- 

 chanter being longer than the other. Upper margins of 

 the meropodites of the ambulatoiy legs transversely rugose. 

 Under surface of the penultimate joints of the second and 

 third legs without patches of hairs , distal part of the ex- 

 ternal margin of the under surface of the penultimate joints 

 of the third legs hairy ; some few hairs on the under mar- 

 gins of the meropodites. Dactylopodites more slender than 



Notes from the Leyden M!u»>eutu, "Vol. III. 



