154 University of California Publications in Zoology [Vol. 23 



Genus Cryptolithod.es Brandt 



Carapace transverse, broadly oval, nearly smooth, high in the middle, and later- 

 ally produced into wide expansions which completely conceal the ambulatory legs, 

 forming a large, expanded dorsal shield. Abdomen flattened, triangular, fitting 

 neatly into a depression of the sternum; behind the entire basal (second) segment 

 the abdomen bends abruptly; the three following segments are divided into a 

 median row of plates, with a series of lateral plates on either side; penultimate 

 segment is devoid of lateral plates, and conceals the minute triangular telson. 



Key to the California Species of Cryptolithodes 



I. Hands tuberculated. Rostrum narrowing distally, end rounded, without dis- 

 tinct anterolateral angles. Abdomen crossed by transverse ridges. (Not 

 known south of Monterey.) 



typicus, p. 154. 

 II. Hands smooth. Eostrum widened toward distal end, which is transverse, with 

 distinct antero-lateral angles, and often but not always with a small median 

 tooth. Abdomen smooth. (Not known south of Pacific Grove.) 



sitkensis, p. 155. 



Cryptolithodes typicus Brandt 



Plate 20, figures 1 and 2 



Cryptolithodes typicus Brandt, Bull. Phys.-Math. Acad. St. Petersb., 7, 

 185, 1849, 11, 254, 1853; Stimpson, Jour. Boston Soc. Nat. Hist., 6, 

 572, pi. 19, 1857; Holmes, Occas. Papers Calif. Acad. Sci., 7, 121, 

 1900; Rathbun, H. A. E., 10, 164, 1904; Way, Puget Sd. Mar. Sta. 

 Publ., 1, 352, fig. 5, 1917. 

 Characters. — Carapace about twice as wide as long, with lateral expansions 

 rarely advanced even as far as half the length of the rostrum, orbital sinus never 

 very deep, never as deep as half the length of the rostrum. Rostrum narrowing 

 distally, end rounded, no distinct anterolateral angle. Hands tuberculated, with 

 several tuberculous ridges on the outer surface. Abdomen crossed by transverse 

 ridges, lateral plates with more or less raised margins. 

 Dimensions. — Type : length 33.9 mm., width 48.7 mm. 



Color. — Blackish brown on dorsal side, light gray on ventral (Way). Several 

 specimens preserved in the U. S. National Museum, greenish in alcohol. 

 Type Locality. — Northern California. 



Distribution. — Unalaska, Alaska, to Monterey, California, to a depth of 7 

 fathoms. 



