FISHERYBULLETIN:VOL.78,NO. 1 



small spines occur along the posterior half of this 

 inner margin. 



Distribution. — Munidopsis aries appears to be a 

 rare, deepwater species. The type is from near 

 Bequia in the Caribbean Sea (lat. 13° N, long. 61.1° 

 W) at 2,912 m. The Oregon specimens were col- 

 lected at 2,850 m in Cascadia Basin and at 3,025 m 

 in Cascadia Channel. 



Munidopsis bairdii (Smith 1884) 



Galacantha bairdii Smith 1884:356 (original de- 

 scription). 



Munidopsis bairdii. Smith 1886:649 (redescrip- 

 tion) pi. 5, fig. 2. 



Munidopsis chacei. Kensley 1968:288 (original 

 description) fig. 1. 



Materia/.— Holotype, USNM 5717, female, 45 mm 

 CL, Albatross stn 2106, 37°41.3' N, 73°3.3' W, 

 2,740 m; USNM 10801, male, Albatross stn 2573, 

 40°34.3' N, 66°09' W, 3,188 m; USNM 171344, 

 male, 48 mm CL, male, 41 mm CL, stn CP-2-B, 

 45°34.5' N, 126°18.5' W, BMT 156, 2,661 m; 

 OSUBI 00193, female, 28+ mm CL, stn CP-2-E, 

 44°43.4' N, 126°27.5' W, 0TB 90, 2,772 m; OSUBI 

 00192, 6 specimens, stn CP-2-C, 45°20.8' N, 

 126°37.7' W, BMT 264, 2,750 m; OSUBI 00194, 

 female, 22 m CL, stn CP-2-D, 44°53.7 ' N, 126°33.4' 

 W, BMT 162, 2,774 m; 51 uncataloged specimens, 

 smallest ovigerous female 43 mm CL. 



Remarks. — The characteristics of Munidopsis 

 chacei Kensley, are within the range of variation 

 of M. bairdii and, therefore, M. chacei is here con- 

 sidered a synonym of M. bairdii. As noted by 

 Kensley (1968), M. chacei and M. bairdii differ in 

 the number of spines of the gastric and cardiac 

 areas and on the posterior margin, and the ratio of 

 dactyl to propodal length of the ambulatory legs. 

 However, the range of variation of these charac- 

 teristics in our specimens of M. bairdii includes 

 those observed for M. chacei (Table 2). 



Munidopsis columbiana Pequegnat and 

 Pequegnat is a closely related species, with the 

 following differentiating characteristics: anten- 

 nal spines present in M. columbiana, absent in M. 

 bairdii; abdominal segments with spines in M. 

 columbiana, absent in M. bairdii; and inner mar- 

 gin of merus of third maxilliped with five to eight 

 teeth in M. columbiana, three teeth in M. bairdii, 

 and two to four teeth in our specimens. 



Table 2. — Selected spine counts of Munidopsis chacei and M. 

 bairdii from their type descriptions, compared with data from 46 

 Oregon specimens. 



Pequegnat and Pequegnat (1971) mention two 

 other characteristics, but these do not separate the 

 two species. In their key, the presence of more than 

 seven spines on the carapace separates M. colum- 

 biana from M. bairdii. In the Oregon specimens, 

 the number of spines on the carapace ranges from 

 5 to 11. The number of lateral spines on the ros- 

 trum is not a distinguishing characteristic. 

 Munidopsis columbiana can have from two to six 

 lateral spines, but usually has four. The type of M. 

 bairdii has six lateral spines. In the Oregon 

 specimens the number of spines ranges from two to 

 six, but usually is four. 



Distribution. — Munidopsis bairdii occurs at 

 depths of 2,377-2,940 m in Cascadia Basin. It has 

 been previously collected in both the Atlantic and 

 Pacific Oceans: Cape Sable to Cape May (Smith 

 1886); Cape Hatteras to Nantucket (Smith 1884); 

 off Panama (Faxon 1895); and off the west coast of 

 the Cape Peninsula or Cape Point, South Africa 

 (Kensley 1968). 



Munidopsis sp. (Figure 3) 



Munidopsis sp. USNM 171345, male, 20 mm CL, 

 stn NAD 17, 44°31.2' N, 125°15.5' W, OT 23, 

 1,829 m. 



Remarks. — Munidopsis sp. closely resembles 

 Munidopsis bairdii, but is distinctly different in 

 some characters. More specimens are needed to 

 verify species status. The form differs from M. 

 bairdii in having no lateral spines on the rostrum, 

 a shorter rostrum, only one spine on the posterior 

 margin, rugae on carapace much less pronounced, 

 hairs on carapace thicker, shorter eyespines ex- 

 tending just beyond the cornea, and the chelae not 

 armed with two inner spines. However, Munidop- 

 sis sp. has four spines on the gastric area and three 

 on the cardiac area, which are within the range 

 found for M. bairdii. 



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