452 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.21 



erosus Rathbun (1898), Balss also proposed a new name, T. rathbunae, 

 for the latter species. Unfortunately, the name that he proposed is also 

 unavailable, having been used previously, with but a difference in termi- 

 nation due solely to gender, by De Man (1903). It therefore becomes 

 necessary to propose still another name for the Rathbun species. 



Range: Eastern Pacific from Magdalena Bay, Lower California, and 

 San Marcos Island, Gulf of California, Mexico, to Esmeraldas, Ecua- 

 dor; Clarion Island, Mexico. Western Atlantic off Havana, Cuba. 

 Indian Ocean: Mauritius, Andaman Sea, western Australia. 



Thyrolambrus glasselli, new name 

 Plate Z 2 , Figs. 8, 8a; Plate 51, Fig. 1 



Thyrolambrus erosus, Rathbun, 1898, p. 579, p. 42, fig. 1 ; 1925, p. 533, 

 pi. 197; pi. 281, fig. 2. Garth, 1948, p. 31. Not T. erosus (Miers), 

 1879 (Parthenopoides). 

 Parthenope erosa, Flipse, 1930, p. 12, footnote; p. 85. 

 Thyrolambrus rathbunae Balss, 1935, p. 128 (name substituted for 

 T. erosus, preoccupied). Not T. rathbuni De Man (1903). 



Type: Female (of 2 males, 2 females) holotype; U.S.N.M. No. 

 21577; length 18.4 mm, width 25 mm, cheliped 29.3 mm. 



Type locality: Off Cape San Lucas, Lower California, Mexico, 31 

 fathoms, Albatross station 2829. 



Localities subsequently reported, with collectors: Gulf of California, 

 Mexico: San Lorenzo Channel, 8 fathoms, and off Ceralbo Island, 10 

 fathoms, Albatross (Rathbun, 1898). Ecuador: off Esmeraldas, 9-27 m, 

 Askoy (Garth). 



Atlantic analogue: Thyrolambrus astroides Rathbun. 



Diagnosis: Margins of carapace thick; hepatic and branchial regions 

 swollen, prominent. Merus of cheliped short, inflated; manus with six 

 triangular, acute teeth on lower border; middle tooth of upper margin 

 largest; fingers short and stout. Resemblance to coralline algae striking. 

 Male first pleopod cylindrical, strongly bent in terminal fourth, tapering 

 abruptly beyond, flaring again before emarginate tip; a double row of 

 stout setae on lip of groove, scattered short setae elsewhere. Male second 

 pleopod about three-fourths as long as first, base swollen, tip short, blunt, 

 with a denticulate concavity. 



Description: Carapace about three-fourths as long as wide, pentag- 

 onal in outline, slightly wider at posterolateral than at anterolateral 

 angles ; lateral and posterior margins thick and lobate, the posterolateral 

 margin nearly transverse and furnished with seven unequal lobes; antero- 



