474 EXPLANATION OF THE LETTERING. 



b.pl Basilar plate. 



br Brain; brain chamber; procephalic lobes. 



bran Branchiae. 



br.c Branchiocephalon. 



br.ct Branchial cartilage. 



b.t Branchial temperature organs. 



b.t.hm or b.t.m Branchiothoracic or hypobranchial muscle. 



b.th.n Branchiothoracic nerve. 



b.v Blood-vessel. 



c""^ Lines of canal organs. 



c Cancelte; corneal membrane; coelom. 



cap Cephalic appendages. 



cap.b Capsuligenous bar of the endocranium; chilarial bar. 



card.g.or cd.g Cardiac ganglion. 



card.in Cardiomeres. 



card.s Cardinal sinus. 



CO Canalis centralis; colar ccelom. 



c.ca Conical pulp cavities. 



c.d Cephalic disc. Cephalic duct. 



c.cl Procephalic ccelom. 



c.cn Collar nerve. 



c.co Cephalic caecum. 



cer Cerebrum. 



cerbl Cerebellum. 



cer.p Cerebral peduncles 



c.f Cranial floor. 



eg Corneagen layer; cephalic ganglia; caudal neuromeres. 



chila Chilaria. 



ch.g Cheliceral ganglion. 



ch.H.c Chelicero-hemisphere cells. 



ch.H.tr Chelicero-hemisphere tracts. 



ch.l Cheliceral lobe. 



chl.b Chilarial cartilage bar of endocranium. 



chlic Chelicerae. 



ch.pl Chilarial pleurite. 



ch.t Chitenous tubule. 



cl Cloaca. 



0.1 Cancellous layer. 



cms Cephalic mesoderm. 



cn Procephalic neuromeres; cancelte. 



cnar or cnv Cephalic navel; dorsal organ; htemostoma. 



cn.c Neural canal; neurocoele. 



cnl Canaliculi. 



CO Commissure. 



co.c Cerebral commissure cells; corona ciliata. 



co.f Cerebral commissural fibers. 



co.n "■ .Nerve to corona ciliata. 



cort Cerebral cortex. 



cox Coxal spurs. 



c.p Collar pore. 



or Branchial cartilage of embryo 



