750 



ARTHROPODA phylum vii 



Suborder B. HYMENOCARINA Clarke. 



Nebalia-like forms with folded univalved carapace ; rostrum loanting {T). 



Family 1. Hymenocaridae Salter. 



Body with eight to nine thoracic and abdominal segments, and six caudal spines in 

 three pairs. 



Hymenocaris Salter (Fig. 1453). Carapace narrow in front, very broad posteriorly, 

 convcx ; >nrface smooth or faintly lined. Cambrian ; Wales and British Columbia. 



Fig. 1452. 

 Nebalia geoffroyi M. Edw. Recent ; Mediterraneaii. s/j. 



Fig. 1453, 



Hymenocaris vermicauda Salter. 

 Upper Cambriau ; Dolgelly, Wales. 

 Vi (after Salter). 



Several peciüiar genera described by Walcott under the names of Hurdia, Tuzoia, 

 Odaraittj Fieldia and Garnarvonia, from the Middle Cambrian of British Columbia, 

 are doubtfiilly referred to this family. 



Suborder C. CERATIOCARINA Clarke. 



Carapace hivalved, with a median Symphysis and a free rostrum. 



Family 1. Oeratiocaridae Salter. 

 Carapace pod-shaped, smooth and without eye-nodes. 



Ceratiocaris M'Coy {Entomocaris Whitf.) (Fig. 1454). Valves of carapace elongate, 

 ^^^^^^s ^^^^^^^^^-^ s^r^'^'-^^ sub-ovate or sub-quadrate, 



narrow in front, sub- 

 truncate, but not in- 

 ■^ curved iDehind. Surface 

 without nodes or carinae. 

 Antennae (?) obscure; sup- 

 posed gastric teeth large, 

 cuspidate. Rostrum 

 lanceolate. Body Seg- 

 ments fourteen or more, 

 four to seven extending 



- ■ ' ot them with obscure 



Fig. 1454. 



n.an.lil.les ; ,, Rostral plate. lA^gfter 



branchial appendages 



