404 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 21 



Measurements: Largest specimen, male: length 63.5 mm, width in- 

 cluding spines 47.7 mm, without spines 43.5 mm, rostrum 13.0 mm, 

 basal width 7.7 mm, width at midpoint 3.6 mm, cheliped 118 mm, chela 

 56 mm, dactyl 21.7 mm, height of palm 13 mm, ambulatory legs 75, 53, 

 46, and 38 mm, respectively. Female: length 40.6 mm, width including 

 spines 30.5 mm, without spines 25.0 mm. 



Color in life: Not recorded. 



Habitat: Sand, shell, broken shell, coralline. (Rathbun) Coarse 

 shelly sand and weed. (Crane) Of the 26 stations of the Velero III 

 and Velero IV at which the species was collected, 13 were sand bottom, 

 6 were coralline, 4 were mud bottom, and 3 were rock bottom. Shell was 

 present with sand in 3 instances, sand with mud in 2, and sand with 

 rock in one instance. 



Depth: Taken once intertidally ; otherwise from 2 to 30 fathoms. 



Size and sex: Males are from 7.3 to 63.5 mm, females from 8.0 to 

 40.6 mm, the single ovigerous female 17.7 mm. The cheliped of the 63.5 

 mm male at 118 mm is almost as long as the 120 mm cheliped of the 

 72 mm male recorded by Rathbun (1925, p. 455) and compares in 

 development with that of the 66.4 mm specimen figured by Rathbun 

 (op. cit., pis. 162, 163). The merus, however, has but four spines above, 

 not five or six as in the description above. The distal broadening of the 

 palm to enclose a digital tooth within a considerable gape apparently 

 occurs only in the very old, for the next smaller specimen, a 42.7 mm 

 male, has the cheliped elongate but slender. 



Remarks: Reasons for considering Chorilibinia angusta Lockington, 

 known only from the original description, to be identical with Steno- 

 cionops contigua (Rathbun) rather than with Libinia mexicana Rath- 

 bun, as Rathbun (1925, p. 310) herself suggested, are as follows: 

 ( 1 ) The orbits are said to be salient and composed of two acute spines. 

 This is true of Stenocionops but not of Libinia, the orbit of which is not 

 salient and is composed of a spine and a cup. (2) The external antennal 

 spine is said to be long and visible in dorsal view in front of the pre- 

 orbital spine. This is true neither of Libinia mexicana, the antennal spine 

 of which is not external, nor of Stenocionops ovata or S. beebei, the an- 

 tennal spines of which are too short to be seen in dorsal view. (3) The 

 chelipeds are said to be slender and about the same length as the first 

 walking legs, the merus provided with four tubercles above, the manus 

 smooth and slender. In Libinia mexicana the chelipeds are considerably 

 shorter than the first walking legs (in the 25 mm size range), the merus 

 unarmed, the manus not tapering nor as rough as the other segments. 



