PART 1 GARTH : PACIFIC OXYRHYNCHA 27 



Habitat: Following a resume of published habitat notes, data con- 

 cerning the substratum from which Hancock expedition specimens were 

 recovered are evaluated. 



Depth: To the bathymetric range previously recorded is added any 

 vertical extension of range noted in connection with the study of the 

 present collection. 



Size and sex: The size range of the species as represented by the 

 material examined, from the smallest young to the largest adult of each 

 sex, with due regard to populations of varying mean sizes in widely 

 dispersed localities. While the significant changes which take place with 

 growth, such as enlargement of the cheliped in the male and the broaden- 

 ing of the abdomen in the female preparatory to egg-bearing, are duly 

 recorded, it is recognized that growth, as a continuous process, was not 

 observed during this study. 



Breeding: The season at which ovigerous females were encountered 

 in the various latitudes. Males were not inspected for the presence of 

 spermatozoa. 



Remarks: Here are discussed relationships, reasons for taxonomic 

 changes proposed, significance of names, and a variety of other subjects. 

 A final sentence is devoted to extension of range. 



Explanation of Measurements 



Measurements were taken by means of a dial caliper and are given in 

 millimeters. 



The length of the carapace is measured along the median line from 

 the posterior margin to the tip of the rostrum in specimens having a single 

 rostral spine, and to a perpendicular connecting the tips of the rostral 

 spines in specimens having a double rostral spine. 



The width of the carapace is measured at the widest part, usually 

 branchial, and is exclusive of lateral spines. In the Acanthonychinae both 

 hepatic and branchial width are given. 



The length of the rostrum is measured along the midline from the 

 level of the hiatus between the preorbital spine (if present) and the base 

 of the rostrum, to the tip of the rostrum. 



The width of the rostrum is measured at its base unless the sides are 

 concave, in which case it is measured at its narrowest part. 



