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PACIFIC SCIENCE, Vol. XXII, October 1968 
Fig. 2. Microdeutopus trichopus sp. nov. isabela island, galapagos. $ Holotype: a, peraeopod 1 ; b, 
telson; d, uropod 3. S Paratype: e, peraeopod 2; f, ventral surface of peraeon segments 3-6. $ Paratype: 
c, peraeopod 1 ; g, peraeopod 2. 
segmented) about equal to the peduncle; acces- 
sory flagellum 2-segmented (some paratypes 3- 
segmented), the first segment elongate, the 
second rudimentary, not extending beyond the 
first segment of the primary flagellum. (In a few 
paratypes it reaches the second segment, when 
the meristematic basal segment of the primary 
flagellum is dividing.) Antennae shorter than 
the antennules, the fourth and fifth peduncular 
segments subequal; flagellum 4-segmented, the 
first segment long, equal to the combined lengths 
of the terminal three. Peraeopod 1 (Figs, lb, c) 
with the coxopodite produced anteriorly, 
rounded; basipodite markedly produced antero- 
proximally; meropodite with very long setae on 
the posterior border. Carpopodite oval, longer 
than broad, with a median dentiform process on 
its anterior margin, and, at the posterior distal 
angle, three stout teeth the most distal of which 
is the longest; propopodite short, with a single 
lobe on the posterior margin; dactylopodite 
relatively long. Peraeopod 2 (Fig. lb) with the 
basipodite concave anteriorly, carpopodite con- 
siderably longer but scarcely broader than the 
propopodite. Peraeopods 3-7 of the usual 
Microdeutopus form. Uropod 3 (Fig. le) with 
the rami subequal and longer than the peduncle; 
exopodite terminal margin with one very long 
