190 U.S. NATIONAL MUSEUM BULLETIN 236 



species of which only the female is known and which has been found 

 at Roscoff along the Atlantic coast of France, has the anal operculum 

 bordered with spinules, according to Monard's description (1935a, 

 p. 45, figs. 87-96), but here again the setal formula, notably of leg 2, 

 is different. 



The species, varieties included, has a very wide distribution, espe- 

 cially in the Atlantic, where it occurs from the Arctic seas, along 

 American, European, and African coasts, down into the Antarctic seas. 

 Its distribution has been discussed by Lang (1948, p. 589) and sum- 

 marized by Sewell (1940, pp. 191-196). Further localities are: the 

 Helgoland area of Germany (Klie, 1941); the Plymouth area of Eng- 

 land (Eraser, 1936; Marine Biological Association, 1931, 1957); the 

 Dalkey area of County Dublin and Lough Ine of County Cork, both 

 in Ireland (Roe, 1958, 1960); Teneriffe in the Canary Islands (Noodt, 

 1955a); the Rovinj, Yugoslavia, area in the Adriatic (Vatova, 1928); 

 the Stalin area on the Black Sea coast of Bulgaria (Caspers, 1951); 

 Leander Point at Port Denison in Western Australia (Nicholls, 1945); 

 and Addu Atoll in the Mai dive Archipelago (Sewell, 1940). Though 

 comparatively few Pacific records are available, the occurrence of 

 this common form in the Ifaluk material is not surprising and fits 

 quite well in the pattern of distribution. The species occured in three 

 sand samples, taken at various intervals from the reef margin at 

 Falarik, and in a sample taken from crevices. 



Family Diosaccidae G. O. Bars, 1906 



The subdivisions of this large family and the definition of its vari- 

 ous genera is complicated slightly by the fact that the Diosaccidae 

 have been treated independently by Nicholls (1941b) and Lang (1944, 

 1948). Lang, when he wrote his monograph, was unaware of Nicholls' 

 paper, but it has been discussed in an appendix to Lang's monumental 

 paper. It seems apparent that Lang's system of subdivisions of the 

 Diosaccidae must be preferred far above Nicholls' attempt. The 

 definition of the various, usually small, generic complexes in Lang's 

 paper is quite clear, based on an appreciation of characters of both 

 females and males and marked by distinctly indicated types. That 

 some of Lang's genera, e.g., his (much reduced) genus Amphiascus 

 G. O. Sars, 1905, sensu Lang, are still heterogeneous is due mainly to 

 our Icnowledge, still far from complete, of its various species. Nicholls, 

 however, has introduced generic names which, for priority reasons, 

 cannot be neglected altogether and shortly will be discussed here. 



Nicholls' genus Alesamphiascus — if we consider how its various 

 species should be distributed according to Lang's monograph — is 

 exceedingly heterogeneous, a fact of which Nicholls already was con- 

 vinced: "This group is a somewhat arbitrary collection of species 



