122 University of California Publications in Zoology [VoL 23 
B. No paired appendages on anterior abdominal segments of either sex. 
Fourth pair of legs subchelate. 
1. Left cheliped much larger than the right; fingers somewhat spooned. 
Dardanus, p. 126. 
2. Left cheliped only slightly larger than the right; fingers acuminate. 
Holopagurus, p. 127. 
II. External maxillipeds widely separated at base. Right cheliped larger than 
the left. (As the characters of the following genera are not equally 
applicable to both sexes, a key including the species of all three is 
given on page 128.) 
A. A pair of appendages on the first abdominal segment either of male 
only or of female only. Fingers of chelipeds opening and closing 
obliquely. i 
1. A pair of appendages on the first and second abdominal segments 
of the male only. 
Parapagurus, p. 144. 
2. A pair of appendages on the first abdominal segment of the female 
only. 
Pylopagurus, p. 142. 
B. No paired appendages on first or second abdominal segment of either 
sex. Fingers of chelipeds opening and closing horizontally. 
Pagurus, p. 130. 
I. External mazillipeds approximated at the base. Chelipeds equal or subequal, 
or left larger than the right. 
Genus Paguristes Dana 
Chelipeds similar, equal, subequal or one (usually the left) may be larger than 
the other. Fourth pair of legs simple. External maxillipeds approximated at 
base. Abdomen with paired appendages other than the uropods on the first two 
segments in the male, and the first segment of the female. 
Kery TO THE CALIFORNIA SPECIES OF PAGURISTES 
I. Eye-stalks moderately stout, two-thirds to three-quarters as long as width of 
anterior portion of carapace. : 
A. Upper surface of hands strongly spined with numerous dark-tipped 
spines. Eye-stalks of more or less uniform width throughout their 
entire length. Teeth of front subequal; rostriform tooth reaching 
about to bases of eye scales. 
1. Hands very broad, only about one-fifth longer than wide, outer 
margin strongly convex; immovable finger at base about twice 
as wide as movable one. (Not known north of San Francisco.) 
‘ bakeri, p. 124. 
2. Hands much narrower, about one-third or more than one-third, longer 
than wide, outer margin but slightly bowed out; immovable finger 
at base subequal or but slightly wider than movable one. 
turgidus, p. 123. 
