6 U.S. NATIONAL MUSEUM BULLETIN 259 



Procedure 



Field work conducted during June 1964, and May and August 1965, 

 was directed particularly toward obtaining specimens from geographic 

 areas from which species of Stygonectes had been previously reported 

 or where new species or range extensions were suspected to occur. 

 Specific areas in Missouri, Kansas, Oklahoma, Texas, and Arkansas 

 were covered during 1964, and similarly, areas in Maryland, Virginia, 

 Pennsylvania, and West Virginia were covered in 1965. Even on 

 trips aimed primarily at collecting Stygonectes, however, material 

 often referable to other genera of amphipods was obtained. A few 

 collections of Stygonectes were made prior to 1964 during field work for 

 the Biological Survey of Virginia Caves, a project which was initiated 

 in 1961 and which is still in operation. 



Primarily, caves were visited on field trips, although in some areas 

 seeps and small springs were the main target. The type of collecting 

 site depended to a large extent on the nature of the underlying bedrock. 

 In areas underlain by carbonate rocks, caves usually provided the 

 best source of material, but in areas of noncarbonate rocks, the seeps, 

 springs, and occasionally wells were investigated. With few excep- 

 tions, specimens of Stygonectes were not abundant in caves and were 

 found only rarely in seeps and springs. Obtaining good collections 

 from seeps and springs almost invariably depended on being at a 

 particular site at just the right time, and this was generally true of 

 my experiences as well as Hubricht's (Hubricht, in Htt.). It would 

 appear that the optimum time for obtaining collections from epigean 

 locahties is in the early spring, and since I was unable to schedule any 

 extended field trips at this time of year, my collections from seeps and 

 springs were, with few exceptions, not particularly profitable. Caves 

 yielded better series of material, but, as already mentioned, even here 

 specimens of Stygonectes (as opposed to Crangonyx and Stygobromus, 

 which were usually obtained in much greater abundance) were often 

 extremely rare, and many potential stygonectid caves yielded poor 

 resiUts or nothing at all. 



Despite the low collection yield of many of the areas visited, the 

 field work was beneficial because I was able to observe first hand a 

 number of previously collected localities and many potential locahties 

 scattered over more than 75 percent of the range of Stygonectes. 

 Field observations were especially valuable in contributing to a more 

 complete understanding of the ecology of this group. 



Three small hand devices were used in collecting amphipods. A 

 Becton-Dickinson "Asepto" syringe (one ounce capacity) with the 

 tip enlarged by previous heating was used to "suck up" material from 

 the water. Contents were then passed from the syringe into a small 



