222 



U.S. NATIONAL MUSEUM BULLETIN 23 6 



samples. The following table shows the size of the specimens re- 

 corded so far. 



In the Ifaluk collection the species occurs in a washing of the alga 

 Lyngbya from the lagoon shelf at a depth of about 6 feet and in a 

 sand sample collected some 340 feet from the reef margin, where the 

 sand was collected from sand pockets between boulders of the elang. 



Genus Rohertgurneya Lang, 1944 



Robertgurneya spinulosa (G. O. Sars, 1911) 



Figures S7a-c, 88 



Amphiascus spinuloses Sars, 1911, p. 388, suppl. pi. 22. — Monard, 1928a, pp. 



379, 386.— NichoUs, 1939, p. 262.— Sewell, 1940, p. 280. 

 Amphiascoides spinulosus. — NichoUs, 1941b, pp. 72, 81, 83. 

 Robertgurneya spinulosa. — Lang, 1944, p. 21; 1948, p. 702, figs. 276 (no. 7), 283 



(no. 1). 



Material. — ^Loc. 592, 2 ad. 99, 0.50 and 0.51 mm. 



Description. — One of the female specimens from locality 592 has 

 been completely described; this specimen has been dissected and 

 mounted. 



Adult female, total length 0.51 mm.; greatest diameter 0.13 mm.; 

 length of longest furcal seta 0.32 mm. 



Body moderately slender in dorsal view, greatest diameter at level 

 of oral appendages, very gradually tapering posteriorly (fig. 87a). 

 Cephalothorax and abdomen of nearly same length, without distinct 

 separation between these two body regions. Head and 1st thoracic 

 somite fused; cephalic somite longer than combined lengths of thoracic 

 somites 2 to 4. In lateral aspect (fig. 876) back only slightly curved, 

 laterally produced to cover basal parts of oral appendages, postero- 

 lateral corner rounded. Rostrum a slender, triangular plate placed 

 in depression of cephalothorax. Rostrum slightly curved, pointing 

 forward, as long as antennular somite 1 and 2. Thoracic somites 2 

 and 3 with slightly produced epimeral plates, cut off squarely; 4th 

 thoracic somite rounded laterally. All thoracic somites with smooth 

 borders. 



