THE BRANCHIOPODA 



35 



The last segment of the boily, or telsoii, cHrries, except in 

 Limnetis and Thamnorephalus, a pair of furcal rami, long anteinii- 

 form filaments in the Notostraca (Fig. 16), unsegmented styles or 

 flattened plates in the Anostraca (Fig. 20, C). In the Conchostraca 

 and Cladocera the posterior part of the body is flexed ventrally 

 and the furca is represented by a pair of strong curved claws 

 (Fig. 17, /). The anus opens either at the end of the body 



--T. 



Fio. 20. 

 A, head-region of Lrpidurns ghmalU from below ; (.', nntenimle ; »", antenna ; gii. j;iiatlio- 

 bas." of lirst trunk-linib ; L, labriim or upper b'p turned forwards (in tlio natural iiositioii it 

 covers the oj.po.sed edges of the mandibles) ; /. lower lip (accordin- to Clans, the inner lobes of 

 the niaxiUulae) ; Yrt, mandible; »w', maxillula ; ,«.r", maxilla. B, posterior end of bodv of 

 LepulKfiisylaciahs ; », position of anal opening : ;)/, sujira-anal plate; /•, rami of caudal fiu'ca ■ 

 V, terminal segment or telson. C, posterior end of body of BriuirJiiiwUi ikiUi^Ii.m ■ letters as 

 above. (After Sars.) " 



between the furcal rami or, in many Cladocera, some distance in 

 front on the dorsal surface. In the genera Lepidurm (Notostraca) 

 and Thamnocephalus (Anostraca) the telson is produced as a thin 

 plate above the anal opening (Fig. 20, B). 



Appendaf/es. — The aniennules are, for the most part, purely 

 sensory in function, not segmented or obscurely so, and carrying 

 tufts of sensory filaments. In many Cladocera they are very small 

 and attached to the posterior surface of the detle.xcd beak-like 



