58 



Gen. 4. Macrocypris, Brady, 1866. 



Generic Characters. Shell very solid, moderately elongate, and acutely 

 produced behind. Inner duplicatures of the valves rather broad, with a narrow 

 transversely striated marginal zone; muscular spots numerous and arranged 

 so as to form together a circular area. Eye wanting. Both pairs of antennae 

 short and robust, the anterior ones 7-articulate and gradually tapering distally, 

 without any sharp demarcation between the basal and terminal parts, setas of 

 the latter part short and stout. Posterior antennae with the terminal part scarcely 

 longer than the basal one, joints rapidly diminishing in size, apical claws slender 

 and elongate. Anterior lip forming in front a rather prominent compressed 

 expansion. Mandibles with the masticatory part rather expanded and coarsely 

 dentate at the edge, palp of moderate size, 4-articulate, and provided at the 

 base with a well developed branchial appendage. Maxillae with both the palp 

 and the masticatory lobes narrowly produced, vibratory plate of smaller size 

 than usual. Maxillipeds with the masticatory lobe very narrow, conical in shape ; 

 palp in female distinctly 4-articulate and armed with 3 slender spines, 2 apical 

 and 1 lateral. Anterior legs with the terminal joint unusually produced and 

 carrying on the tip 2 unequal claws accompanied by a thin bristle. Posterior 

 legs with the outer apical seta rather slender and elongated, recurved spine 

 almost extending to the base of the leg. Caudal rami very small and rudi- 

 mentary, in the form of 2 thin lappets hinging down from the end of the 

 body, and scarcely at all movable, each lappet provided with a limited number 

 of thin bristles. Copulative appendages of male lamellar, and of comparatively 

 simple structure. Ejaculatory tubes very long and narrow, extending along the 

 dorsal face of the body to beyond the middle of its length, each tube provided 

 with numerous short radiating spikes, which however do not form distinctly 

 defined whorls, proximal extremity of the tube bulbously dilated; efferent duct 

 very long, being immediately on its exit from the tube curled up in a dense 

 spiral coil with highly chitinised walls. 



(Tjj Remarks. This genus was established in the year 1866 by Brady, t3 

 include the form originally recorded by Baird as Cythere minna and subsequently 

 (1865) redescribed by the present author, but erroneously referred to the genus 

 Bairdia Me Coy. As pointed out by Brady, the present Ostracod differs in 

 reality very decidedly from the species of that genus, and on the whole approaches 

 much closer to the typical Cypridae, than does the above-named genus. Only 

 a single 'species, strictly referable to the present genus, has as yet come undt 

 my notice, 



