664 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.47. 



latter clearly differentiated in young females, but in older adults 

 absorbed into the trunk. 



Fii-st antennae indistinctly three-jointed, the basal joint enlarged; 

 second antennae with a two-jointed exopod and a one-jointed en- 

 dopod, the latter much longer than the former. 



Mouth tube a broad cone, overlapping the tips of the second an- 

 tennae; fii'st maxillae bipartite and rather stout, without a palp. 

 Second maxillae narrow, but each maxilla with thi'ee longitudinal 

 muscles, as in the preceding species. Maxillipeds with a broad tri- 

 angular basal joint and a short terminal claw. Just behind the base 

 of each maxilhped is a spoon-shaped appendage as large as tho entire 

 head and attached to the ventral surface of the head by a narrow 

 base. In nearly all the preserved specimens these appendages pro- 

 ject from the head like a pair of enormous ears, but in one speci- 

 men they are tm^ned forward and laid down over the mouth parts as 

 though to protect them. Kurz says that in the live animal they pro- 

 ject hardly at all. He calls them sucking disks and says that they 

 have the same form and structure as the lunules in Caligus. He 

 does not show such a structure, however, in the figure given, and 

 certainly in the present and the preceding species they have nothing 

 resembling that structure (see p. 662). When inflated and standing 

 out sidewise, they cause the head to look something like a pawn- 

 broker's three-ball sign. 



Color (preserved material), yellowish-white. 



Total length (without egg strings), 8 mm. Length of cephalo tho- 

 rax, 4 mm.; of trunk, 4 mm.; of egg strings, 3.6 mm. Width of 

 cephalothorax at base, 1.65 mm.; of trunk, 2.8 mm.; of egg strings, 

 1.65 mm.; of second maxillae, 0.5 mm. 



Specific characters of male. — General form ovoid, head at the pointed 

 end; cephalothorax and anterior trunk covered with a carapace, pos- 

 terior trunk turned at right angles and terminating in a pan- of anal 

 laminae. Fii'st antennae indistinctly jointed; second antennae bira- 

 mose and no longer than the first pair, endopod bluntly rounded, 

 exopod two-jointed and ending in a minute chela; fii-st maxillae bi- 

 partite and without a palp ; second maxillae longer than the maxilli- 

 peds and projecting well from the ventral surface, with a slender 

 terminal claw; genital process wide and long, its sides roughened by 

 many ridges and grooves. 



Color, a grayish-white. 



Total length, 0.66 mm. Greatest width, 0.33 mm. 



{occidentalism western, being the fiirst species from the Pacific coast 

 of North America.) 



ReTnarTcs. — ^The facts brought out in the description of these two 

 species enable us to supplement and correct the interpretations of 

 Kr0yer, Hesse, and Kurz in the following particulars : 



