398 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



where that author states that " next the GymothoidcBj though as a type 

 of a separate family, the genus Anthura must be placed." 



The species of this family may be at once recognized by the peculiar 

 cup-like termination of the body. This cup or "flower" is formed by 

 the telson below, and the uropods at the sides and above ; the outer 

 rarni of the latter organs being placed nearly vertically, and approach- 

 ing each other on the median line above, where, however, the "flower" 

 is more or less imperfect. Our three genera may be distinguished as 

 follows : First five segments of pleon consolidated above, Anthura (p. 104) ; 

 segments of pleon distinct, antennae and auteunulae subequal, ParantJiura 

 (p. 108) ; segments of pleon distinct, antennulse greatly enlarged in the 

 male, Ptilanthura (p. 111). 



Anthura Leach. 



Anthura Leach, Ed. Encyc., vol. vii, p. "404" (Am. ed., p. 243), "1813-'14." 

 Antennulae and antennae short, subequal ; thoracic segments not 

 separated by constrictions ; pleon with the five anterior segments con- 

 solidated above and resembling the last thoracic segment. 



Our species of Anthura appears to agree in all generic characters with 

 A. gracilis Leach upon which the genus was founded. In A. polita, how- 

 ever, the consolidated portion of the pleon is seen at the lower part of 

 the sides to be composed of five consolidated segments, and bears the 

 normal number of pairs of pleopods, while Bate and Westwood* say that 

 " the four anterior segments are soldered closely together " in A. gracilis, 

 and that " the pleopoda consist of, at least, four pairs of oval plates, 

 strongly ciliated, on each side of the ventral surface of the basal seg- 

 ments of the tail." They had not, however, fresh specimens of the spe- 

 cies, which is evidently closely related to ours. 



The incubatory pouch of the females in the genus is confined to the 

 third, fourth, and fifth segments, and is composed of three pairs of 

 lamellae, which overlap from behind forward, while the anterior margins 

 of the first pair are united to the anterior part of the third segment. 



Anthura polita Stiinpson. 



? Anthura gracilis Dekay, Zool. New York, Crust., p. 44, pi. ix, fig. 34, 1844 (not of 



Montagu and Leach). 

 Anthura polita Stimpson, Proc. Acad. Nat. Sci. Phil., vol. vii, p. 393, 1856. 



Harger, Proc. U. S. Nat. Mus., 1879, vol. ii, p. 162, 1879. 

 Anthura brunnea Harger, This Report, part i, p. 572 (278), 1874. 

 Verrill, This Report, part i, p. 426 (132), 1874. 



PLATE XI, FIGS. 68 and 69. 



This species is distinguished among its allies on our coast by the nearly 

 complete union of the basal segments of the pleon, which have together 

 the appearance of an eighth thoracic segment. The cup or "flower" at 

 the end of the body serves to distinguish it from other Isopoda. 



* British Sessile-Eyed Crustacea, pp. 157 and 160. 



