U. S. NATIONAL MUSEUM 



PROCEEDINGS. VOL. 80. ART. 15 PL. 4 



10 mm 



ROBERTSONIA CHESAPEAKENSIS AND CRYPTOPONTI US GRACILIS 



A-I, Roberhonia chesapeakensis: A, Dorsal view of female; B, ventral surface of posterior body 

 showing rudimoiitarv sixth legs and spines on posterior margins of segments; C, second antenna, 

 1) mandibular palp'; E, maxilliped; F, first swimming leg; O, second leg; H, fifth leg. 



J-S, Cryptopontius (iracilU: J, Dorsal view of female; K, dorsal view of male; L, first anteiina of 

 female; M, second antenna; N, mouth tube; O, f.rst maxilla; P, second maxilla; Q, maxUlipccl, 

 R, first swimming leg; S, fourth leg. 



