54 Rowland M. Shelley 



now realize are only coincidental similarities between the gonopods of 

 shelf or di and those of certain forms of Cleptoria, based on the shor- 

 tened acropodites and other derived features of shelfordi, which just 

 happen to resemble aspects of Cleptoria gonopods. Consequently, these 

 statements about a relationship between Brevigonus and Cleptoria must 

 now be discounted. 



This paper presents amended diagnosis of both Brevigonus and 

 shelf ordi, a description of arcuatus, and new information on generic and 

 specific ranges. All specimens of arcuatus included in this study are 

 deposited in the North Carolina State Museum (NCSM) collection, the 

 invertebrate catalog numbers of which are shown in parentheses. Other 

 materials are in the collection of Richard L. Hoffman (RLH), Radford 

 University, Radford, Virginia. 



Brevigonus Shelley 

 Brevigonus Shelley 1980:32-34. 



Type species. — Cleptoria shelf ordi Loomis 1944. 



Description. — The following comments on gonopods are supplemental 

 to the somatic description in my 1980 account, and present a parallel 

 treatment to the description of Sigmoria (Shelley 1981a), thus facilitat- 

 ing comparisons. 



Gonopods in situ either crossing in midline or extending forward in 

 subparallel arrangement over anterior edge of aperture and between 7th 

 legs. Coxae large, without apophysis, connected by membrane only, no 

 sternal remnant. Prefemur generally large, with or without large, cuneate 

 process arising on dorsal side. Acropodite thick and heavy, either curv- 

 ing broadly through flattened peak into moderate distal zone and form- 

 ing arc with variable diameter, or terminating abruptly at distal extrem- 

 ity of peak, with distal zone and apical curve absent; basal zone 

 relatively long; anterior bend broad, moderate to poorly defined; peak 

 flattened to gently curved; apical curve broad, smoothly continuous 

 with peak; distal zone moderately long, curving broadly into arch of 

 acropodite and directed toward basal zone, tapering smoothly apically. 

 Termination variable; in forms with distal zone, either narrowly rounded, 

 simple tip, or reflexed tip; in forms without distal zone, broad, blunt, 

 occasionally notched tip. Basal sone usually with prominent basal spine 

 on ventral surface and flange of variable width and configuration on 

 medial face, arising proximally and continuing to termination on peak; 

 latter with or without small acute spur at termination point of flange. 

 Distal zone with remnant of lateral flange extending from proximal por- 

 tion to about 2/3 length, usually represented by thickened rim near 

 outer margin. Prostatic groove arising in pit on prefemur, crossing to 

 lateral side of acropodite at anterior bend and continuing to terminal 

 opening on simple or reflexed tips, or on distal extremity of peak. 



