54 SVEN LOVEN, ON TOURTALESIA, A GENUS OF ECIIINOIDEA. 



like, narrow laminiT, with shortened, acutely triangulai- inner portions, and lengthened, 

 slightly widened, and spinons outer portions. In Aceste, Moira and Schizaster japonicus 

 another peculiarity is met with. Ttie inner portion of each laraella has its margins 

 thickened and compact on the under surface, and produced on either side into a tooth, 

 which in the Schizaster, fig. 102, 103, is strong and directed inward, in Moira, ^ic/. 95, 

 hardly perceptible. Between the thickened margins the under surface is concave, and 

 the upper, in Aceste, raised into a projecting keel, fig. 97, 98. It is worthy of remark 

 that in Schizaster fragilis scarcely a rudiment is to be seen of the whole of this 

 conformation, which no doubt serves to extend the attachment of motor muscles. 



Among the Prymnodesmians, Metalia, fig. 106, has frontal pedicels nearly like 

 those of Abatus. A conformation, similar to that just described in Schizaster, reappears 

 in Kleinia luzonica Gray, whose long and well-developed frontal pedicels end in a 

 large disk, deeply divided into thirteen to iifteen rays, corresponding to a like number 

 of lamina?, fig. 99, resembling those in Moira, only a little broader, of a more open 

 texture, and more spiny at the margins. Their inner exti-emities are also spade-like, 

 with two distinct marginal teeth. In Brissopsis lyrifera the strong frontal intra- 

 fasciolar pedicels likewise terminate in a large and flat circular disk, Pl. IX, fig. 86 — 89, 

 with a waved margin, the regular undulations of Avhich answer to an equal number 

 of fifteen to eighteen radiating laminte, resembling those of Schizaster fragilis, subrect- 

 angular in their longer, external portions, compact, smooth-margined and tapering 

 to an obtuse point in their internal contiguous portions, and devoid of the marginal 

 teeth seen in Kleinia. The circular space in the centre generally is perfectly clear, 

 — numerous observations had indeed made me assured that it were so invai'iably, till 

 one specimen turned up, presenting the calcified lamina delineated in fig. 86. Accor- 

 ding to notes taken long ago, accompanying the figures here given of the disk, as it 

 appeared in the living animal, these lamels are inclosed in the homogeneous substance, 

 outside which is seen a complexity of connective tissue and nervous elements, together 

 with interspersed pigmentary nucleated cells, fi^g. 88, some deep red, others yellow. 

 This texture extends to the inside of the epithel. In the interstices betAveen every 

 two laminffi there is seen an oblong granular body, opaque by transmitted light, white 

 by reflected light, having all the appearance of a glandular inass, although, at the time, 

 I could not find an excretoiy opening. In specimens preserved in spirits it has dis- 

 appeared almost completely. It may perhaps secrete some viscous substance, by which 

 minute a,nimals are captured that live above the surface of the clay in which the Spa- 

 tangus is deeply burrowing, while the tops of these highly extensible, prehensile organs 

 are playing freely in the water high above. Alone among the species hitherto exa- 

 mined, Agassizia scrobiculata, Pl. X, fig. 93, has frontal intra-fasciolar pedicels similar 

 to the subanal. Almost of the same size with these, they likewise end in a circle of 

 filaments of unequal length, with rods as slender, and tops as tumid, surrounding a 

 cup-like protuberance with tive tinangular lobes converging into a central depression, 

 and overlying a rosette of radiating lamina3. 



Echinocardium presents a rather peculiar form of frontal pedicels. In Echino- 

 cardium flavescens O. F. M., Pl. XI, fig. 127 — 130, their structure was observed already 



