320 Proceedings of Eoyal Society of Edinburgh. [sess. 
Crozets, is assigned by the describer to the same species, var. 
echinata , var. nov. Of this he says : — “ The close affinity of this 
form to its far distant type in the North Atlantic is especially 
remarkable; whilst the manner in which some of its characters 
approach even more nearly that of P. mirnicus from the North 
Australian sea are very striking, and, at the same time, highly 
suggestive of the genetic connection of the three forms.” P. mimi- 
cus is also a deep-water asteroid, from 800 fathoms, north-west of 
the Aru Islands. 
Dytaster exilis , Sladen. — This asteroid belongs to a widely- 
distributed genus, all whose species come from deep water (in one 
case only from so little as 800 fathoms) from the North and South 
Atlantic, North and South Pacific, and the Eastern Archipelago. 
In regard to the species cited, the type came from 1375 fathoms 
between Valparaiso and Juan Fernandez. A form was got in 
1900 fathoms off Tristan d’Acunha, in regard to the single example 
of which the describer says (Pep., p. 68): — “This I propose to 
rank provisionally as a variety of this form, although it may after- 
wards be found to merit recognition as a distinct species ” ; while, 
lastly, specimens were taken in 1700 fathoms in the North 
Atlantic, off Maryland, which are described as a variety consider- 
ably nearer than the other to the type-species. We have to do, 
in short, with a very widely distributed form, very variable, or 
rather comprising forms only provisionally linked together ; while, 
even if we still do link them, the range of distribution is not 
shown to be greater than 35-37 degrees of latitude to south and 
north. 
Ophioglypha irrorata , Lym. — I have not found a reference to 
the occurrence of this species in the northern hemisphere. 
Ophioden sericeum , Lym. — A specimen doubtfully referred to 
this species was got off Marion Island, 50-75 fathoms. This is a 
small but well-known and common northern species, nevertheless. 
Mr Lyman, in describing the “ Challenger ” specimens, of which 
there were two (Pep., p. 79), calls attention to their variations and 
to the difficulty of distinguishing them from allied forms; and 
indeed marks with a query the identifications at the head of his 
paragraph. He closes the paragraph by citing without further 
remark as a locality “off Marion Island, 50-75 fathoms.” 
