22 University of California Publications in Zoology [Vol. 23 



Characters. — Eostrum exceeding eyes, but falling short of antennular peduncle; 

 above ciliate and armed with nine to ten teeth, -below with two small teeth near 

 depressed tip; rostrum continued backward as a carina nearly to posterior margin 

 of carapace and sulcate posterior to last tooth. Carapace with sulcus parallel to 

 and on each side of dorsal carina, continued forward from posterior extremity of 

 dorsal carina onto lateral ridges of rostrum; outer margins of sulci more promi- 

 nent near last rostral tooth and distinctly flared outward. Telson acute, deeply 

 sulcate above, and devoid of lateral spines or spinules; greatly exceeded by the 

 uropods. 



Dimensions. — Length 42 mm., carapace 10 mm., rostrum 5 mm. (Kingsley). 

 Of specimen examined by Holmes, length from tip of rostrum to tip of telson 

 182 mm. ; carapace, including rostrum, 41 mm. ; rostrum 24 mm. 



Type Locality. — Estero at Bealijo, west coast Nicaragua (salt water). 



Distribution. — San Francisco Bay, California to Panama; Galapagos Islands. 

 To a depth of 51% fathoms (Eathbun). 



Genus Benthesicymus Bate 



Eostrum short, elevated, compressed; if armed, toothed above only. Outer 

 edge of basal joint of antennular peduncle armed with one or two spines; no 

 scale on inner edge; antennular flagella longer than the carapace. Mandibular 

 palp foliaceous, two-jointed, second joint narrower and shorter than the first. 

 Exopodites of second maxillipeds much longer than endopodites; endopodites 

 subpedif orm with last three joints more or less flexed on the merus. Exopodites 

 on all the legs decreasing in size posteriorly until they become rudimentary on 

 the last pair of legs. 



Key to the California Species of Benthesicymus 



I. Median carina of fifth and sixth abdominal segments terminating posteriorly 



in a small acute tooth. 



tanneri, p. 23. 



II. Fifth and sixth abdominal segments devoid of teeth; posterior margin of sixth 



segment raised to form a peculiar transverse ridge. 



altus, p. 22. 



Benthesicymus altus Bate 



Plate 11, figure 2 



Benthesicymus altus Bate, Ann. Mag. Nat. Hist., (5), 8, 191, 1881; "Chal- 

 lenger" Eept., Zool., 24, Macrura, p. 336, pi. 58, fig. 1, 1888; Faxon, 

 Mem. Mus. Comp. Zool., 18, 203, 1895. 



Characters. — Eostrum short, compressed, apex styliform, crest thin and armed 

 with two teeth, continued back as a carina as far as the cervical groove, posterior 

 to which the dorsal surface is smooth and rounded; last three abdominal segments 

 much compressed, the fourth but slightly carinated, more so on the posterior half 

 than anteriorly, the sixth segment with a small but decided carina, which fades 

 out before it reaches the transversely elevated posterior margin. 



Dimensions. — Type, female: length 120 mm. 



Type Locality. — Between Australia and New Guinea, 1400 fathoms ("Chal- 

 lenger" station 184). 



Distribution. — South Pacific; Philippines; Japan; South Atlantic, off Tristan 

 da Cunha; 500 to 1900 fathoms (Bate). Gulf of Panama; west coast of Central 



