252 bulletin: museum of comparative zoology. 



SPATANGIDAE Agass. 



PALEOPNEUSTIDAE A. Ag. 

 Phrissocystis multispina A. Ag. and Clark. 



Prom an unknown station there are a large number of fragments of at least two, 

 and possibly three, individuals of a species of Phrissocystis, which must have been 

 of very large size, probably from 100-150 mm. in length. They are of a rich red- 

 brown color and carry long spines with a reddish tinge. This species resembles 

 P. aculeata A. Ag. in having no subanal fasciole and in the arrangement of the 

 abactinal system and the ambulacra. It appears to differ from that species, not 

 only in color, but in the much larger number of primary tubercles on the abactinal 

 plates (8-12 instead of 4-8) and in the very large actinostome, which in one in- 

 dividual is 35 x 16 mm. 



Meijerea excentrica A. Ag. and Clark. 



This species is very similar to Phrissocystis, but has a well-developed subanal 

 fasciole. As Doderlein (1906) has suggested, this difference necessitates a new 

 genus which he has called Meijerea, with Phrissocystis humilis de Meijere as the 

 type species. The Hawaiian specimen is evidently not humilis, as it is much flatter 

 and more heart-shaped, with the abactinal system considerably posterior to the 

 middle of the test. The subanal fasciole is also different ; it encloses an open 

 rectangular area, 4.5 mm. wide, with the base 24 mm., and the sides 10 mm. in 

 length. The test is 74 mm. long, 60 mm. wide and only 17 mm. high, and the 

 abactinal system is 39 mm. from the anterior edge. The color is light brown, 

 with whitish primary spines. 



Station 4039. Off Kawaihae Light, Hawaii, 670-697 fathoms. 



One specimen. 



Pycnolampas A. Ag. and Clark. 



This genus is established for some delicate little Spatangoids, which, although 

 apparently immature, do not appear to be the young of any known species, and 

 seem to require a new genus for their reception. It is most nearly allied to 

 Homolampas, but differs from that genus in the entire absence of any anterior 

 furrow or depression, and in the subpetaloid character of the posterior ambulacra. 

 The test is ovate, rather flat anteriorly, higher posteriorly, and is thin and fragile. 

 There are a very few large primary spines in the anterior and lateral interambu- 

 lacra, abactinally, but neither they, nor those of the actinal surface, have sunken 

 scrobicular circles or show any pits (as in Lovenia) on the interior of the test. 

 Abactinal system compact. Ocular plates conspicuous. Anterior ambulacrum 

 indistinct, not at all depressed, and with few, minute pores. Poriferous zones of 

 the other ambulacra evident, those of the posterior ambulacra especially, tending 

 to become petaloid. Subanal and peripetalous fascioles present, distinct but 

 narrow. No genital openings are visible. 



