NO. 2 WALTON : THE GENUS PYLOPAGURUS 145 



Fourth pair of thoracic legs subchelate, rasp restricted to distal mar- 

 gin, not developed on outer face of hand; fifth pair minutely chelate, 

 rasp developed on outer surface of propodus and fingers. 



Abdomen straight, membranous, over twice as long as thorax, terga 

 not present except in poorly calcified caudal chield. 



Telson symmetrical, rather poorly calcified, smooth, outline almost 

 a half-circle except for prominent notch in terminal margin, a strong, 

 downward curving, flattened tooth at each end of notch, with setae and 

 smaller denticles along sides toward apex; uropodal peduncles short, 

 heavy, anterior pair of blades over twice length of posterior pair, both 

 sparsely setose along anterior and posterior margins. 



Measurements: Total length (rostral point to tip of abdomen) 33 

 mm; length of carapace 4.3 mm; length of precervical portion 2 mm; 

 length of major manus 5.9 mm; width of major manus 2.3 mm; length 

 of carpus 4.2 mm; width of carpus 1.7 mm; length of minor manus 2.4 

 mm ; width of minor manus 1 mm ; length of dactyl second thoracic leg 

 3.6 mm ; length of propodus second thoracic leg 2.9 mm. 



Distribution: Known only from the Gulf of California at Angel 

 de la Guardia Island and Consag Rock at the following stations. 



541-36 5 

 1057-40 66 

 1068-40 1 



The bathymetric range was from 24 to 60 fathoms. 



Discussion: This species is very closely related to P. holmesi, and, 

 as in that species, there is a considerable variation in the ratio of length 

 to width, especially of the major cheliped. The extremely long narrow 

 form of the cheliped is typical of adult males, apparently the result of 

 heterogonic growth. Each growth stage results in the addition of a 

 considerable increment at the terminal margin with only a slight addi- 

 tion to the width. This is apparent to a lesser degree in other appendages 

 and in the body itself. The younger forms tend toward an ovoid rather 

 than a spatulate hand and in the females the over-all proportions and 

 appearance are often practically identical with the females of P. holmesi; 

 in fact, they are often distinguishable only with considerable difficulty. 



Remarks: With the exception of a few juveniles, this species was 

 taken only in the chitinous tubes of the polychaete Hyalinoecia juvenalis 

 Moore. 



