PART 1 garth: pacific oxyrhyncha 123 



Supplementary description : The following is not necessarily at 

 variance with the earlier descriptions of Stimpson and of Rathbun, but 

 will serve to translate their generalities into specific terms. The re- 

 latively short rostrum occupies between one-sixth and one-seventh of 

 the postrostral portion of the carapace, the ratio in the male being 

 1 : 6.33, in the female 1 : 6.45. The first ambulatory leg is less than 

 three times the total length of the carapace, the ratio in the male being 

 2.61 :1, in the female 2.75:1. The dactylus of the first ambulatory leg 

 is between one-fifth and one-sixth the length of its propodus, the ratio 

 being 1 :5.5 in both sexes. The dactylus of the fourth leg occupies 

 slightly less than half the length of its propodus in the male, slightly 

 more than half in the female. The gradual shortening of the walking 

 legs, which decrease regularly in the male in the ratio of 2.6, 2.2, 1.8, 

 and 1.6 times the carapace length, and the relative attenuation of the 

 hinder pair is characteristic of the species. The number of clusters of 

 curved hairs which may be counted along the anterior margin of the 

 propodus of the first walking leg varies from 6 to 8. 



In arriving at the foregoing proportions, a female specimen of 14.9 

 mm and a male of 12.6 mm were used. The latter, while larger than 

 the specimen measured by Rathbun, is by no means mature. Crane 

 (1937, p. 52) records a male and female from the Gulf of California 

 measuring 21.5 mm and 20.0 mm, respectively. In view of the absence 

 of specimens of similar size among Hancock expedition material, the 

 following is extracted from her description: 



"The rostrum, instead of being rounded, is bilobed in all the 

 specimens, the lobes being conspicuous and unequal in the large male 

 and female; . . . along the margins of the rostrum is a row of spinules 

 . . . The vermiculations [of the sternum] are spinulous, especially in 

 the large specimens. 



"The cardiac protuberances of the adults are higher and more com- 

 pressed and scarcely continued forward ; the hepatic and pterygostomian 

 lobes are relatively more developed ; the outer margin of the basal 

 antennal article is more conspicuously bi-lobed ; and, finally, the manus 

 of the adult male is considerably, instead of slightly, swollen, the fingers 

 gaping instead of meeting at the base." 



Crane asserts that the characters mentioned as at variance with 

 earlier descriptions may be attributed to the greater age of the speci- 

 mens. With this the present writer agrees, and, having examined the 

 large male from Zaca station 136, would add that the bilobation of the 

 front is not as striking a character as one might be led to believe from 



