316 AMPUirODA NOJIIXALIA. 



Fam. 2. PHRONIMIDiG. 



Inferior antennae obsolete, in one sex at least. Third pair of 

 pereiopoda developed into a more or less perfectly chelate organ. 



This family ct)rrcsponds with Dana's, exchi-sively of the genus 

 Phorcus. It may be conveniently di%-ided into two subfamilies. 



Subfamily 1. PHRONIMIDES. 



Ha^-ing the three posterior pairs of pleopoda biramous ; rami lan- 

 ceolate. 



• This subfamily corresponds with Dana's division PHR0NmiN.E, 

 exclusively of the genus Primno. 



1. PHRONIMA. 



Phronima, Latrcille, Hist. Nat. Crust. \\. p. 289, 1803. 

 Phronyma, Leach, Sam. Ent. U, Cu))ip. p. 101. 



Cephalon large, broad at the top, tapering inferiorly to the oral ap- 

 paratus. Pei'eion broad and flat. Pleon narrow. Eyes on the dorsal 

 surface of the cephalon. Superior antennae short, two-jointed ; in- 

 ferior antennae obsolete. Mandibles without an appendage. Gna- 

 thopoda more or less complexly subchelate. Pereiopoda consisting 

 of but six joints : first two pairs of pereiopoda simple : third having 

 the dactylos fused with the propodos ; the propodos and carpus 

 developed into a perfectly-formed chela : fourth and fifth pairs 

 imifonn, shorter than the third. Three posterior pairs of pleopoda 

 biramous, lanceolate. Telson single. 



1. Phronima sedentaria. (Plate LI. fig. 1.) B.M. 



Cancer sedeutarius, ForsJcal, Descript. Anim. p. 95. 



Cancer (Gammarelius) sedentarius, Herbst, Naturij. der Krabben, ^c. 



ii. pi. 37. f. 8. 

 Phronima sedentaria, LatreiUe, Gen. Crust, et Ins. i. p. 30. pi. 2 ; 

 Hist. Nat. des Crust. \\. p. 289. 



Lamarck, Hist, des Anim. sans Vert. v. p. 197. 

 Desmarest, Consid. sur les Crust, p. 257. pi. 45. f. 1 (after ^mo). 

 Edtcards, Ann. des Sc. Nat. xx. p. 394, (2nd ser.) iii. pi. 14. f. 9 ; 

 R^qne Anim. Cuvier, 3rd ed. pi. 58. f. 8 ; Hist, des Crust, iii. p. 93. 

 pl.'SO. f. 13. 

 Lucas, Expl. dans VAlqerie, t. 5. f. 5. 

 White, Cat. Crust. B.'M. 1847, p. 50. 

 Spencc Bate, Si/nopsis, ^-c, Aim. Nat. Hist. Feb. 1857. 



Antennae not so long as the cephalon ; fii-st joint short, second four 

 times as long. First pair- of g-nathopoda ha^ing the meros inferiorly 

 produced, with the margin serrated ; carpus infero-anteriorly pro- 



