PART 1 GARTH : PACIFIC OXYRHYNCHA 451 



pared in the description above. Decidedly, P. (P.) stimpsoni is not a 

 crested species, the margins of the chelipeds and of the walking legs 

 being thickened rather than compressed. Individual teeth on the new 

 species appear as if inflated rather than as if hammered out as in P. (P.) 

 excavate Some difference in basic proportion is also evident, particularly 

 in the cheliped, the individual segments of which appear to be longer 

 and narrower than in P. (P.) excavata. The totally different male first 

 pleopod is perhaps the most striking character separating the two species. 

 It was while examining the male copulatory appendages that the species 

 was recognized as new. 



Genus THYROLAMBRUS Rathbun 



Thyrolambrus Rathbun, 1894b, p. 83; 1925, p. 531. Balss, 1935, p. 128. 



Parthenomerus Alcock, 1895, p. 280; type: P. efflorescens Alcock, 1895, 



by monotypy. 

 Parthenopoides Miers, 1879c (part), in Bouvier, 1915, p. 52. Flipse, 



1930, p. 85. 

 Type: The Atlantic Thyrolambrus astroides Rathbun, 1894, type of 

 Thyrolambrus Rathbun by monotypy. 



Description : Carapace broader than long, deeply eroded. Frontal and 

 anterolateral regions strongly deflexed. Surface covered with irregular 

 pits. Basal [segment] of antenna elongate, reaching or nearly reaching 

 level of inferior orbital hiatus. Maxillipeds broad, fitting close together 

 and filling the buccal cavity; ischium subrectangular posteriorly, inner 

 anterior angle produced ; merus broader than long, first [segment] of 

 palpus fitting transversely a slight notch at anterointernal angle; re- 

 mainder of palpus concealed by merus. Chelipeds of moderate length; 

 manus less stout than merus and armed on inner side with two rows of 

 spines or long tubercles continued on the fingers. (Rathbun, 1925, modi- 

 fied) 



According to Balss (1935, p. 128) : "The type of the subgenus Par- 

 thenopoides Miers (1879c, p. 672) is Lambrus massena Roux, which, 

 however, belongs to the subgenus Pseudolambrus Paulson 1875, which 

 was founded four years previously. Parthenopoides accordingly becomes 

 a synonym of Pseudolambrus and can not, as Bouvier would have it, be 

 used, according to the international rules of nomenclature, for other 

 species. Bouvier's two species Parthenopoides erosus Miers and P. cariei 

 Bouvier therefore belong to the genus Thyrolambrus Rathbun." Since 

 the name Thyrolambrus erosus (Miers, 1879) had priority over T. 



