REPORT ON THE ECHINOIDEA. 205 



The two Challenger specimens were still covered with spines at the time I examined 

 the " Blake " Echiuoidea, and it was only subsequently that I became aware of their 

 identity. On the actinal plastron the primary spines are spathiform, the spines of the 

 anterior part of the test of the actinal and abactinal surface are longer than the others, 

 curved, gradually diminishing in size towards the apical system, though longer again on 

 the edge of the petals ; the sides of the test are covered with smaller spines increasing 

 in length again towards the actinal keel and the anal face of the test. Within the 

 peripetalous fasciole the spines are of an ashy violet tint and a silvery dull white over 

 the rest of the test. 



The facies of this species seems to indicate closer affinities of the genus Periaster 

 to Schizaster than to Linthia with which I was (as Desor before me) inchned to 

 associate it. 



Station 188. September 10, 1874. Lat. 9° 59' S., long. 139° 42' E. ; 28 fathoms; 

 mud. 



*Moiropsis (Moira) n. gen. 



This genus has, like Moira, a peripetalous fasciole forming a seam immediately on the 

 edge of the petals ; it has also, like it and other Schizasteridee, a weU developed latero-anal 

 fasciole, the odd anterior ambulacral petal well limited and similar to the others, and 

 the petals sunken. This genus is intermediate between Moira and Schizaster, and shows 

 that the affinity of these genera is far closer than had been suspected. 



'■"Moirojms daudicans (PI. XXXVI. figs. 4-7; PI. XL. figs. 51-53). 

 Schizaster daudicans, A. Agassiz, 1879, Proc. Am. Acad, vol. xiv. p. 211. 



This pretty little Schizaster is well characterised by the high posterior test, the 

 vertical posterior extremity extending into a prominent beak (PI. XXXVI. fig. 6), the 

 sharp, narrow, clear-cut lateral fasciole, the narrow and deeply-sunken ambulacral petals 

 fringed by an indistinct peripetalous fasciole (PI. XXXVI. figs. 4, 7), its narrow actinal 

 plastron (PL XXXVI. fig. 5), the position of the anal opening immediately under the 

 abactinal edge of the posterior interambulacral keel, and the close uniform tuberculation of 

 the test above the ambitus. The outline of the test is cordate, seen from the actinal side 

 (PL XXXVI. fig. 5) broad, the ambulacral areas bare ; the actinostome placed close to the 

 anterior edge, about one-fourth of the length of the test. The peripetalous fasciole crosses 

 the odd posterior and lateral posterior interambulacra close to the apical system, following 

 the edo-e of the petals it crosses the anterior iuterambulacrum halfway in the petal and 

 encloses the whole of the short anterior petal, which is shorter than the lateral anterior 



