A >i mil* of fJie Month African 



Neolampas, but now that I have examined specimens, it seems to 

 me this interesting form had best be placed in a genus of its own, 

 although its relationship to Neol<nii]><is is evident. It differs from 

 Neolain-pus in the complete absence of any anal furrow or pit, the 

 periproct being Hush with the surface of the test, in having 

 4 distinct genital pores and in the complete shutting out of the 

 oculars from the abactinal system, the live pairs of interambulacral 

 plates forming a closed ring surrounding the fused plate formed from 

 the genitals. The oculars are greatly reduced and I failed to detect 

 any ocular pores. 



The most striking character however, though it may prove to be 

 specific rather than generic, is the development of a sunken brood- 

 pouch in the female. This appears to be formed by the imagination 

 of the fused genitals with their surrounding ring of interambulacral 

 plates, so that the genital pores lie on the lloor of the pouch, whose 

 wall is thin and carries very few spines. The pouch itself is about 

 1-5 mm. deep and "2-3 mm. in diameter; the entrance is about half 

 the diameter. Relatively large spines and pedicellariae guard the 

 entrance but are outside of it. In one female, whose pouch I opened, 

 there was a single young one, nearly circular in outline, slightly 

 llattened, about I '5 mm. in diameter, covered with many primary, 

 but few rniliary, spines and with a central circular mouth. In the 

 males, there is no pouch but there may be a slight depression of 

 the proximal end of interambulacrum 5. Studer speaks of it as a 

 shallow groove concealed by overcrossing spines but it is not at all 

 noticeable in his ligure nor in any of the PIETER FAURE specimens. 



There are four well marked genital pores. Studer says the left 

 anterior pore is noticeably smaller than the others but it does not 

 seem to be so in any of the present specimens. Again, Studer says 

 the peristome is covered by naked skin, but probably he did not 

 dry a specimen, for when the membrane is dry it is found to be 

 lilled with thin calcareous plates. In his description of the basico- 

 ronal plates around the peristome, Studer does not refer to the large, 

 glassy sphaeridia, one of which lies in a big, shallow pit at the 

 middle of each ambulacra! margin. 



The miliary spines of Tropholampas are (like those of the other 

 Nucleolitidae) similar to those of the Laganidae, in being made up of 

 parallel rods, connected by cross-bars, and more or less expanded, 

 llattened and toothed at the free end. Each spine is made up of 

 six such rods in Tropholampas and each rod is so much expanded 

 at the tip that the whole spine is abruptly three times as thick at 

 the tip as elsewhere. While the miliary spines are thus noticeably 



