



RECENT BRITISH OSTRACODA. 



3<VJ 



The following synopsis of the sections and families here described is riven b\ 



o 



Sars : 



f simple, subpediform, geniculate, clawed 

 at the apex, not very unlike the upper 

 antennae. Both pairs of antennae either 

 bearing long setae and adapted for swini- 



or shortly setose and not used for 

 swimming. Mandibles distinct, mostly 

 strongly toothed at the lower extremity ; 

 palp of moderate size, and bearing a more 

 or less developed branchial appendage. 

 First nair of maxillae 



P 



O 



r. 



— 



z 



I 



) two pairs, 

 valves. 



the last bent up within thai 



rning, 



Postabdoniun forming two elon- | n yi , ttln v 

 gated narrow rami, which are usually [ 

 clawed at the apex. J 



1 



pair 

 branchial plate. 



Feet 



bearing a large 



)>three pairs, all ambulatory, much alik 

 in structure, and directed forwards. I N - 

 abdomen rudimentary, forming two fery 

 small lobes. Antenna) very little adapted 

 for swimming. 



'ODOCOPA. 



« I mi 

 r]\)a:. 



r 



one 



branch 





3 



j 



i 



o 



rudimentary, immo- 

 bile ; the other elongated, cylindrical, 

 flexible, many-jointed, armed with 

 long natatory setae, arranged in a 

 single series ; basal portion very large 

 and stout, filled with muscular bands. 

 Upper antennae scarcely natatory. 

 Mandibular palp very large, genicu- 

 late, subpediform, destitute of a bran- 

 chial appendage. First pair of jaws 



without a branchial plate. Post- 

 broad 



j 



("one pair only, of singular shape, forming 



an elongated, curved, flexible, annulat. t, 



vermiform appendage, which is spiniferou 



towards the apex. Upper antenna} lai 



distinctly jointed, geniculate at the base. 



Mandibles proper obsolete. Second pair 



of jaws bearing a large bronchial plate. 

 Eyes compound, pedunculated, widely 

 separated ; between the two in front a 

 large simple eye and a short frontal ten- 

 tacle. 



Cypridi- 



mda;. 



abdomen divided 



plate, 

 into two 



plates, which are unguiferous behind. 

 Feet 



J 



two pairs, the posterior very small and 

 rudimentary ; the anterior provided, like 

 the second pair of jaws, with nalL 

 lobed branchial plate. Upper antenna ot ^Cok cm 8 



the female small and weak, immobile and \ ciad;* 

 indistinctly jointed. Mandibles distinct. 

 Xo eyes. Frontal tentacle very large, and 

 mostly dilated at the apex. 



MYODOCOPA. 



> 



POLYCO- 



PIDJE. 



w 



both branches well developed, moveable, and natatory. Upper antennae also 

 natatory, not geniculate, ending in a lash of long set®. Mnndibl distinct, palp 

 short and scarcely pediform, provided with a small branchial append* . 1 wo 

 pairs only of thoracic appendages; the anterior large, bind, natatory : the poste- 

 rior membranaceous and branchial Eyes wanting. Postabdomen divided int. 

 two short laminse, spinous behind. 



flattened, similar to the feet of the Copepoda, basal portion biarticuhy an' 



geniculate ; branches flattened, composed of few joinl and beam numerous 



set» on both margins. Upper antennae very fcree and strong, many-jo m • 



geniculate at the base, shortly spiniferous. Mandib es small **™*f W < 



Three pairs only of thoracic appendages, all maxdlilonm ^**»™3™ I iim | 



and first jaw bearing internally a comb of large sete. First and con mi 



jaws provided with a large branchial plate ; third pan rmlnncnta > 1 1 i i- ■ 



in the male well developed and prehensile. Postabdominal rami small and 



narrow, distinctly separated, and spiniferous at the apex. 



CLADOCOPA. 



CvTirr:- J PLAT YCOPA 



Section I. PODOCOPA. 

 Fam. 1. Otpbjdm, 



Upper antennte mosth 



Valves mostly thin and smooth, more or >-*»£££, brush of . rcatl , , lesi 



seven- jointed, and beset with numerous setse, which toim a dense , 



length; lower antenna, geniculate and bent backwards, four- or fi ^""^£^J£ 



dUtal extremity with from three to five long, subtly curved c a^a n ^ -g 



the posterior aspect 



of the antepenultimate joint 



bundle of seta? 



Powerful, and divided at the 



^Xinto sever, teeth, bearing .*£-£« 



r~»w±ui, una aiviaea at me eiucuuu; Twnmirsof i 



Palp, the first joint of which is provided with a branch, append £_»" 1-J ] 



*e first large", and divided into four digital segments, tl 



la i 



than 



the rest, two-jointed and giving attachment to 



anterior segment being 

 i large branchial plate: 



