ORAL APPENDAGES OP BIARINE ISOPODA. 87 



second and third joints are very large. The inner distal lobe extends for- 

 ward slightly beyond the middle of the second joint of the palp, and distally 

 it has a number of setose spines. The epipodite is a wide flattened plate, 

 with almost parallel sides ; it is wider than the basipodite. Its apical portion 

 curves outwardly slightly and extends forward as far as a point a little beyond 

 the middle of the second joint of the palp. 



18. Synidotea pallida, Benedict. (PI. 9. figs. 38, 39.) 



Synidotea pallida, Benedict, Proo. Acad. Nat. Sci. Philad. 1897, p. 396 ; Richardson, 

 Bull. No. 54, U.S. Nat, Mus. 1905, p. 378, figs. 412, 413. 



The First Maxilla (PL 9. fig. 38). — The outer lobe exhibits a strong inward 

 curve. It has eight terminal spines, all of which are denticulate, and there 

 are a few seta3 on the inner anterior margin. The inner lobe is compara- 

 tively small ; terminally there are two long setose spines. 



The Maxillipede (PI. 9. fig .'59). — Miss Richardson's figure of the maxilli- 

 pede of this species is incomplete and very unlike the actual appendage. 

 The divisions of the eoxopodite are small. The basipodite is small, but does 

 not slope outward quire so much as in the preceding species, and the second 

 joint of the palp is smaller, the third joint is twice the length of the 

 second one ; the inner distal lobe is also narrower than in S. hirtipes. The 

 epipodite is a wide flattened plate with its apical portion narrowed and slopino- 

 outwards ; it extends as far forward as the anterior margin of the second 

 joint of the palp. 



19. Synidotea nebulosa, Benedict. (PI. 9. figs. 40, 41.) 



Synidotea nebulosa, Benedict, Proc. Acad. Nat. Sci. Philad. 1897, p. 397 ; Richardson 

 Proc. U.S. Nat. Mus. vol. xxi. (1899) p. 848; Bull. No. 54, U.S. Nat. Mus. 1905,' 

 p. 381, figs. 416, 417. 



The First Maxilla (PI. 9. fig. 40). — -The outer lobe has a strong inward 

 curve. There are ten terminal spines, most of which are denticulate ; there 

 are a few setae on both the outer and inner margins. The anterior portion 

 of the inner lobe is roughly triangular with the distal end obliquely cut away 

 and terminating in two stout setose spines. 



The Maxillipede (PI. 9. fig. 41). — The shape of the basipodite at once 

 serves to separate this species from any other member of the genus. The 

 second joint of the palp is very large, but the anterior lateral margins are 

 not so expanded as in S. hirtipes. 



20. Synidotea angulata, Benedict. (PI. 9. figs. 42, 43.) 



Synidotea angulata, Benedict, Proc. Acad. Nat. Sci. Philad. 1897, p. 395; Richardson 

 Bull. No. 54, U.S. Nat. Mus. 1905, p. 382, figs. 418, 419. 



The First Maxilla (PI. 9. fig. 42). — The strong inner curve of the outer 



