KONGL. SV. VET. AKADEMIENS IIANDL. BAND. 19. N:0 7. 89 



graduolly passes iiito the rounded flanks. These general features are those of Schizaster 

 canaliferus, the frontal sinus tliat of Sch. fragilis. — The perisouie, iipon t,he whole 

 disposed like that of Schizaster ^), is in soine points considerably modified. The in- 

 terradials 2 and 3, which, as in that genus, form the ridge bounding on either side the 

 great dorso-frontal depression, enter the peristome, as normal, each with a singie small 

 plate, foUowed by a pair of larger ones, of which the outer one is broad, the inner 

 narrow. Then come, in 2 a and 3 b, two fair-sized plates, and a terminal row of 

 eleven or tAvelve very minute plates, that look as if coalescent into three or four 

 slender and compressed, articulated plates, making the very top of the ridge. The 2 

 b and 3 a, of nearly equal hreadth throughout, Avith the last four or five plates leng- 

 thened, form the inner slope of the ridge, adjoining the frontal ambulacrum. The in- 

 terradia 1 and 4 are very much as in Schizaster canaliferus, Sch. japonicus and Sch. 

 fragilis, the plate 1 being subtriangular and internally extended so as to reach the 2, 

 while in 1 a the heteronomy is effected by the union of 2 and 3 into a singie plate. 

 In the interradium 5 the labrum is someAvhat longer than in Schizaster or Moira. The 

 sternum is less broad, the episternal angle distinct, the abdominal a plates a little be- 

 hind the b plates, the periproct being formed by b 5, 6, 7, a 4, 5, 6-, the anal mem- 

 brane, jig. 236, covered Avith rounded scales, has the excretoi'y opening someAvhat above 

 the centre. — In the ambulacral system the III, sunk in the large and open depression 

 of the forepart, is lanceolate, very broad, even more so than in young Schizasters, and 

 expanding aborally. The II and IV are narrow, their lirst seven pairs of plates of a 

 fair size; they terminate, not Avith a petaloid, sunken expansion of transverse plates, 

 but Avith a strongly compressed double series of minute plates, longer than they are 

 broad, level Avith the adjoining interradia, and bearing pores placed adorally and 

 diagonally throughout, indistinct or perhaps partly Avanting in the intra-fasciolar por- 

 tion of the inner roAv. The bivious ambulacra I and V are rather broad in the ventral 

 part, I a 2, b 3 and Y b 2, a 3 being larger than the rest, I a 5 and Y b 5 entering 

 the episternal angle, the terminal part gradually tapering, apetalous, the plates about 

 as broad as they are long, sub-hexagonal, the minute pores placed near the adoral 

 margin. — The peristome is normal, ficj. 235, transversely oval, altogether anterior, upright, 

 vertical, not ventral. The scales covering the buccal membrane are larger frontally, 

 the oesophageal opening transversely oval. someAvhat below its centre. — The calycinal 

 system, jig. 237 , placed on the apex of the body, a little behind the three fourths 

 of the total length from the front margin, comes more near to that of Schizaster cana- 

 liferus, jig. 238, than to that of Moira, in Avhich the distortion of the system is 

 carried very far. It is a little broader than it is long, the 1 and 4 being prominent. 

 In the specimen described the 1 and 2, and the 3, 4, 5 are united severally, only one 

 suture being visible, connecting the radials I and III. The I and 4 each have a large 

 sexual pore. The madreporite is central. — The singie fasciola, simple and undivided 

 all around, ansAvers to the peripetalous fasciola of Schizaster. Very nearly as in 

 that genus it tra verses III, 3, 4, 2 b 4, 2 a 4, 5, ^ a 4, ^ b 4, II 7 and IV 7, 8, 

 ') Études, pl. XXXI fig. 194. 



K. Vet. Akail. Ilaiidl. Band in. N:n 7 12 



