1921] Schmitt: The Marine Decapod Crustacea of Califorma 23 
America;: Galapagos Islands; 1360 to 2232 fathoms (Faxon). Off San Nicolas 
Island, California; 1350 to 2182 fathoms (‘‘ Albatross’’ station 4390). 
Remarks.—In Bate’s figure of this species there appears to be a small spine 
on the side of the carapace although none is mentioned in his description. In the 
‘« Albatross’’ specimens there is no spine at this place (Faxon). 
Benthesicymus tanneri Faxon 
Benthesicymus tanneri Faxon, Bull. Mus. Comp. Zool., 24, 215, 1893; Mem. 
Mus. Comp. Zool., 18, 205, pl. H, 1895; Rathbun, H. A. E., 10, 147, 1904. 
Fig. 10. Benthesicymus tanneri, g, lateral view of carapace, X 4 (after 
Faxon). 
Characters.—Rostrum short, acute, laterally compressed, raised above the orbit 
into a crest, which is armed with two slender, acute teeth; rostral crest continued 
backward as a sharp keel on the median line of the carapace, as far as the cervical 
groove, behind which it is obsolescent. First three abdominal segments of the 
abdomen are thick, rounded, and devoid of dorsal carina, or tooth; the fourth 
faintly carinate but not toothed; the fifth and sixth distinctly carinate and armed 
with a small, acute posterior tooth; telson short, convex above, and armed with 
three pairs of lateral spinules. 
Dimensions.—Type: length 112 mm.; length of carapace 44.5 mm.; of rostrum 
8 mm. 
Color—When alive deep red, with a large patch of bright blue on the back 
of the second, third, and fourth abdominal segments; eyes black (Faxon). 
Type Locality—Gulf of California, 905 fathoms (‘‘ Albatross’’ station 3436). 
Distribution—From off San Diego, California, to Ecuador; Galapagos Islands; 
331 to 1322 fathoms (Rathbun). 
Remarks.—This species is very similar to B. altus, and regarding it Faxon 
says: ‘‘In this species the carina on the fifth and sixth abdominal segments 
. terminates posteriorly in a small acute tooth, whereas in the preceding species, 
B. altus, these segments are destitute of teeth, the posterior margin of the sixth 
rising to form a peculiar transverse ridge.’’ 
Genus:-Gennadas Bate 
Very similar to Benthesicymus. Exopodites of second maxillipeds only about 
as long as endopodites, which have a thin, broad, expanded oval merus, beneath 
which the three terminal joints are concealed when flexed. 
KEY T0 THE CALIFORNIA SPECIES OF GENNADAS 
I. Rostrum armed with a single tooth; dorsal carina distinct nearly to posterior 
margin of carapace. ; 
= = borealis, p. 24. 
II. Rostrum armed with two slender, acute teeth; dorsal carina fading out before 
reaching cervical groove. 4 e 
8 = pectinatus, p. 25. 
