CALIFORNIA STALK-EYED CRUSTACEA. 37 



not entirely concealed when retracted. Basal antemial joint moderately 

 dilated and armed with an antero-external spine, the distal portion not 

 entirely covered by the rostrum. Merus of maxillipeds distally truncated 

 and not produced at the outer angle. Ambulatory legs rather slender, 

 subcylindrical, and of moderate length; dactyls nearly straight, acute. 

 Abdomen in the male seven-jointed. 



This genus is divided into two subgenera as follows: 



Herbstia: Inferior margin of orbit not dentate. Ambulatory legs not 

 spinose. 



Herbstiella ST.: Inferior margin of orbit armed with a tooth or spine. 

 Merus of ambulatory legs spinose. 



The subgenus Herbstiella to which our species belong 

 is almost exclusively West American. 



Herbstia (Herbstiella) camptacantha St. 



Herbstia parvifrons STIMPSON, Ann. N. Y. Lye. Nat. Hist., Vol. VII, 1860, 



p. 185 (not H. parvifrons RANDALL). 



Herbstiella camptacantha STIMPSON, 1. c., Vol. X, 1871, p. 94. 

 Herbstia camptacantha A. MILNE-EDWARDS, Miss. Sci. au Mex., Vol. I, Pt. 



V, p. 78, PI. XVIII, fig. 3. 

 Herbstia (Herbstiella) camptacantha MIERS, Journ. Linn. Soc. London, 



Vol. XIV, 1879, p. 655; Challenger Reports, Vol. XVII, 1886, p. 49. 



RATHBUN M., Proc. U. S. Nat. Mus., Vol. XVI, 1893, p. 79. 

 Fisheria depressa LOCKINGTON, Proc. Cal. Acad. Sci., Vol. VII, 1877, p. 72. 



Carapace ovate, punctate, much flattened, and armed above with several 

 small tubercles. Median region tumid, separated from the branchial and 

 cardiac regions by deep sulci and armed, in front, with four tubercles in a 

 transverse line, the middle tubercles separated from each other by about 

 twice the distance that they are from the lateral ones; a median, rounded 

 tubercle on the posterior portion of the median area; three, or four small 

 tubercles on the cardiac region and about five on each branchial region; 

 two tubercles, in a transverse line, on the intestinal area. Rostral horns 

 flattened and divergent, forming more than one-half the length of the 

 rostrum. Preorbital spine acute; there is a small spine, or tooth, on the 

 margin of the orbit above the postorbital tooth, while below it there is a 

 spine on the inferior orbital margin. The spine at the antero-external 

 angle of the basal antenual joint is prominent, and on the margin behind 

 it there ate two spines, the posterior of which is sometimes reduced to a 

 small, blunt tooth. Beside the postorbital tooth the antero-lateral mar- 

 gin is furnished with about five spines, and there are several smaller ones 



