332 



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



Ajy. 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 waU of the mesosoma. 

 Cam. Camerostome (chitinized upper lip). 

 Con. Convexity of the lateral region of the 

 prosoma. 

 cp. CoxaJ pivot. 

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

 metaplastral process. 

 Ec or ec. Entapophysial ligament. 



Ect. Cut portion of the same ligament. 

 Envx. Entocoxite. 

 Enfi-Enf. The seven entapophyses. 

 gd. 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. 

 L Lamellae, forming the " gill-book " of a 

 mesosomatic appendage. 

 lat. scl. Lateral sclerite. 

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

 cornu. 

 l.p.c.en. Latero-posterior process of plastron, or 

 lateral metaplastral process. 

 M. Mouth. 



mh. Membrane of attachment of the pygal 

 muscles. 

 m, n, 0, 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). 

 nist. Mesosomatic tergitc. 

 mtst. Metasternite or " chilaria." 



N. Network of chitin on the inner surface 

 of the carapace. 

 Na. Angle of the posterior carapace belong- 

 ing to metasomatic area. 

 0. Aperture of the branchial blood-vessel 



into the venous collecting sinus. 

 oe. (Esophagus. 



01. Outer lobe of a mesosomatic appendage. 

 P. Plastron or thoracic entosternite. 

 p. Chitinous sclerite on mesosomatic appen- 

 dage. 

 p.ah.st. Postabdominal, or metasomatic sternite. 

 Pb. Posterior border of the thoracic carapace. 

 ph. Posterior border of an entocoxite. 

 Pc. Pericardium. 

 p.c.ea. Posterior process of the plastron or 



lateral metaplastral process. 

 p.in.st. Pro-sternite. 



jri: Posterior process of a mesosomatic ento- 



ehondrite. 

 prs. Prosomatic sternite. 

 PT. Metasomatic tergite. 

 R. Rectum. 



r. Ventral ridge of a mesosomatic ento- 

 chondrite. 

 Ri. Ridge on the inner surface of the tho- 

 racic carapace. 

 S. Muscular stomach, 

 s'-s". Mesosomatic entochondrites. 

 Sf or sf. Subfrontal sclerite. 

 sfa. Subfrontal area. 

 .«;). Postanal spine or " pyge " {wyii). 

 stg. Aperture (stigma) leading into the hoUow 

 tendon of a branchio-thoracic miiacle. 

 T. Tergite. 

 ts-ts^'-. The hollow tendons of the branchio- 

 thoracic muscle. 

 Ve or ve. Venous collecting sinus. 

 W. WaU 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. Intor-entapophysial. 



References to Muscles. 



4 a. Muscle from first to second entapophysis. 

 4 b. From first to third eutapoph3'sis. 

 4 c. From first to fourth entapophysis. 

 4 d. From first to fifth entapophysiii. 



