HEMIASTERIDAE. 159 



Homolampas fragilis. 



Lissonotus fragilis A. Agassiz, 1869. Bull. M. C. Z., 1, p. 273. 

 Homolampas fragilis A. Agassiz, 1872. Rev. Ech., pt. 1, p. 137, 348. 



Plate 146, fig. 8. 



This is the West Indian species and has been taken at depths ranging from 

 300 to 1920 fms. The pedicellariae are not abundant on the available material 

 and show no extreme forms. The rostrate have the margin of the base of the 

 valve (PL 146, fig. 8) smoothish or with very low teeth. The tridentate are 

 not separable into stout and slender. The rostrate valves are .35-.60 mm. long, 

 while in the tridentate they are .20-.70 mm. 



Homolampas hastata. 



A. Agassiz, 1898. Bull. M. C. Z., 32, p. 81. 



Plate 146, fig. 7. 



This Panamic species has been taken only in depths of 978-1132 fms. 

 The pedicellariae are scarce on the available specimens but such as there are 

 resemble those of fragilis. The margin of the base of the valves (PL 146, fig. 7) 

 in the rostrate pedicellariae is, however, provided with quite evident sharp 

 teeth. I have not had sufficient material to enable me to decide whether this 

 is a constant specific character or not. 



• 

 Homolampas rostrata. 



De Meijere, 1902. Tijd. Ned. Dierk. Vereen, (2), 8, p. 14. 



This is the curious species collected by the Siboga, south of the St r ait of 

 Makassar, in 299-386 fms. 



HEMIASTERIDAE, fam. nov. 



This family corresponds to that section of the Spatangidae which Gregory 

 calls the Prymnadetinae. Its one characteristic feature is the entire absence 

 of a true subanal fasciole. There is often a fasciole below the periproct but its 

 relationship is with the peripetalous fasciole, with which it often connects on 

 either side and there is no trace of a subanal plastron. It is by no means certain 



