332 



ME. W. B. S. BEXHAM ON THE MUSCULAR 



Ap. Aperture leading to the space between 

 the two plates forming a mesosomatic 

 appendage. 

 ar. Anterior process of the mesosomatic 

 sternite. 

 c. Chitinous bar in mesosomatic appen- 

 dage. 

 Ca. Canal in the side wall of the mesosoma. 

 Cam. Camerostome (chitinized upper lip). 

 Con. Convexity of the lateral region of the 

 prosoma. 

 cp. Coxal pivot. 

 d.c.en. Dorsal process of the plastron, or dorsal 

 metaplastral process. 

 Ec or ec. Entapophysial ligament. 



JEct. Cut portion of the same ligament. 

 Enc.e. Entocoxite. 

 EnP-Ent 1 . The seven eutapophyses. 

 gel. Genital duct. 

 gp. Genital pore. 

 il. Inner lobe of a mesosomatic appendage. 

 Int. Intestine. 

 K. " Knob " of entocoxite, to which the 



tergo-coxal muscle is attached. 

 L. Liver and genital organ. 

 I. Lamella;, forming the "gill-book " of a 

 mesosomatic appendage. 

 lat. gel. Lateral sclerite. 

 l.c.en. Lateral cornu of plastron, or proplastral 

 coruu. 

 l.p.e.en. Latero-postorior process of plastron, or 

 lateral metaplastral procoss. 

 M. Mouth. 



mb. Membrane of attachment of the pygal 

 muscles. 

 m, n, o, p, q, r, s, t, y, z. Portions of the plastro- 

 coxal muscles 32-14. 

 ml. Median lobe of a mesosomatic appen- 

 dage (part of the sternal wall pro- 

 duced). 

 mst. Mesosomatic tcrgite. 

 mtgt. Mctastornite or " chilaria." 



N 



Network of chitin on the inner surface 





of the carapace. 



No 



Anglo of the posterior carapace belong- 





ing to motasomatic area. 







Aperture of the branchial blood-vessel 





into the venous collecting sinus. 



ce 



(Esophagus. 



01 



Outer lobe of a mesosomatic appendage. 



P. 



Plastron or thoracic entosternite. 



1>- 



Chitinous sclerite on mesosomatic appen- 





dage. 



p.ab.st 



Postabdominal, or metasomatie sternite. 



Pb 



Posterior border of the thoracic carapace. 



pb. 



Posterior border of an entocoxite. 



Pc. 



Pericardium. 



p.c.en. 



Posterior process of the plastron or 





lateral metaplastral process. 



p.m.st. 



Pro-sternite. 



pr. 



Posterior process of a mesosomatic ento- 





chondrite. 



prs. 



Prosomatic sternite. 



PT. 



Metasomatie tcrgite. 



B. 



Eectum. 



r. 



Ventral ridge of a mesosomatic ento- 





chondrite. 



Bi. 



Ridge on the inner surface of the tho- 





racic carapace. 



S. 



Muscular stomach. 



.^-s 6 . 



Mesosomatic entochondrites. 



Sf or sf. 



Subfrontal sclerite. 



sfa. 



Subfrontal area. 



sp. 



Postanal spine or " pyge " (vvyii). 



stg. 



Aperture (stigma) leading into the hollow 





tendon of a brauchio-thoracic muscle. 



T. 



Tergite. 



ts -ts Yl : 



The hollow tendons of the brauchio- 





thoracic muscle. 



Ve or ve. 



Venous collecting sinus. 



W. 



Wall of mesosoma. 



X. 



Portion of mesosomatic sternite. 



X. 



Point of attachment of mesosomatic 





appendage. 



1. Dorsal entapophysio-plastral. 



2. Ventral entapophysio-plastral. 



3. Ventral longitudinal. 



4. Inter-entapophy.sial. 



References to Muscles. 



4 a. Muscle from first to second entapophy sis. 

 4 b. From first to third entapophysis. 

 4 c. From first to fourth entapophysis. 

 4 d. From first to fifth entapophysis. 



