SHALLOW- WATER STARFISHES 117 



On the contrary, the sessile condition of the young in the species 

 of Leptasterias insures greater safety, and though the eggs are much 

 fewer in number, a far greater per cent will reach maturity. 



This method of propagation precludes the rapid diffusion of such 

 species, for they can only migrate by means of the slow method of 

 creeping by the use of their ambulacral feet, unless accidentally 

 carried, attached to floating objects. Under these conditions any 

 local variations that may arise, unless harmful, are likely to be per- 

 petuated by inheritance and isolation. As a matter of fact, many such 

 varieties are already known, some of which may be quite localized, 

 so far as known, while others, probably of much earlier origin, are 

 diffused from Puget Sound to the Aleutian Islands. 



Very extensive collections along the whole coast are needed before 

 the real status of many of the varieties in this group, as well as in 

 Henricia and Pteraster, all of which carry their young, can be settled. 



Our present collections are quite inadequate. The most that we 

 can now do is to describe and figure those varieties that we happen to 

 obtain and that seem worthy of recognition. 



It is not to be supposed that they will be found constant, nor that 

 intermediate forms will not occur. That coast seems to be one vast 

 nursery for new varieties and subspecies. 



Some of the odd forms are probably hybrids between distinct 

 species, but at present there is no way to determine this. Some of the 

 forms classed in Leptasterias may eventually prove to be the young 

 of larger species of Asterias proper, for the latter all pass through 

 a Leptasterias-like stage in the course of their growth. It is impossi- 

 ble, in many cases, to distinguish these young forms without larger 

 series of intermediate sizes. The only positive criterion, in many 

 cases, would be the position of the genital pores and the incubation 

 of the young, which have not been observed in many species. 



LEPTASTERIAS ( ?) INEQUALIS Verrill, sp. nov. 

 Plate LXXIII, figure 2 ; text-figures 4, 5. 



The type is a small five-rayed starfish with depressed, rapidly 

 tapering and rather acute rays. Radii, 7 mm. and 26 mm.; ratio, 

 i : 3.71. 



The dorsal ossicles are lobate, numerous, mostly flat and closely 

 united, leaving small papular areas, and not distinctly reticulate in 

 arrangement. The larger plates in the median and intermediate rows 

 are convex and more prominent. The apical plates are smaller than 

 in epichlora of the same size ; hence the rays are more acute. The 



