PROC. ENT. SOC. WASH., VOL. 24, NO. 2, MAR., 1922 79 



McMurrich, 1895. Embryology of Isopods. Jour. Morphol, 21, p. 63. 

 Philiptschenko, 1912. Embryonalentwicklung von Isotoma. Zeit. Wiss. 



Zool, 100, p. 519. 



Prell, 1913. Chitinskelett von Eosentomon. Zoologica, 1913, p. 1. 

 Racovitza, 1907-1908. Isopodes. Arch. Zool. Exper., 4, ser., 7, p. 145, 9, 



p. 238. 

 Raymond, 1921. Appendages of Trilobites. Mem. Conn. Acad. Arts & Sci., 



7, p. 1. 

 Stummer-Traunfels, 1892. Mundwerkzeuge der Thysanuren. Sitzb. K. 



Akad. Wiss. Math. Nat. Classe, Abt. 1, 1891. 



ABBREVIATIONS. 



a Laciniadentes or incisor processes of lacinial region. 



b Midappendix, or median appendage of lacinial region. 



be Basendite, or endite of crustacean basipodite; lacinia of insectan maxilla. 



bp Basipodite of crustacean limb; stipes of insectan maxilla. 



ce Coxendite, or endite of crustacean coxopodite. 



cp Coxopodite of crustacean limb; cardo of insect's maxilla. 



crp Carpopodite of crustacean limb. 



dp Dactylopodite of crustacean limb. 



ec Eucardo, or subdivision of cardo of maxilla. 



ei Endites of crustacean limb. 



en Endopodite of crustacean limb; maxillary palpus of insect. 



ep Epipodite of crustacean limb. 



es Eustipes, or subdivision of maxillary stipes. 



ex Exopodite, or outer branch of biramous crustacean limb. 



ie Ischiendite, or endite of ischiopodite of crustacean limb; galea of insect's 



maxilla. 



ip Ischiopodite of crustacean limb; palpifer of insect's maxilla, 

 le Lacinulae, or lamellar processes of lacinial region, 

 me Merendite, or endite of meropodite of crustacean limb, 

 mp Meropodite of crustacean limb, 

 pc Paracardo, or subdivision of cardo of maxilla, 

 pp Propodite of crustacean limb, 

 ps Parastipes, or subdivision of stipes of maxilla. 



EXPLANATION OF PLATES. 



Figures 4 and 7 are after Boas, 1883; Figs. 15, 16, 20, 21, 23, 24, 26, 27, 28, 30, 

 and 31 are after Boerner, 1908; Fig. 2 is after Caiman, 1896; Fig. 29 is 

 after Claus, 1889; Fig. 5 is after Daday, 1910; Fig. 19 is after Escherich, 

 1905; Fig. 3 is after Korschelt and Heider, 1890; Fig. 17 is after Prell, 1913; 

 Fig. 22 is after Racovitza, 1908; Fig. 6 is after Raymond, 1921; Figs. 9 

 and 14 are after Stummer-Traunfels, 1892. 



Fig. 1 A trunk limb of crustacean Apus productus. 



Fig. 2 First thoracic limb of crustacean Anaspides tasmaniae. 



Fig. 3 Maxilla of crustacean Calanella sp. 



Fig. 4 First maxilla of crustacean Nebalia bipes (terminal portion cut off). 



Fig. 5 Maxilla of female of crustacean Cypris denticulata. 



