li.') I 



life. '-'-"/i. Tlu' lino seen arioss llic \iMilral Iraiisvorsc rods is tile lower liniit of 

 the suboral lavily. 

 Fig. t). ^■oull{^ larva of Anlropijga jiuhuiuilii (l.amk.). ."> davs olil; vciilral view. Drawn 

 from life, ""/i- 

 7. Larva taken ijelagieaily, probably belonging to Aslromiya pulvinata. .Seen in some- 

 what (ibliqne side view. Some disloeation has oeeurred; the anal area is somewhat 

 twisted to the left so that the side area of the larva has beeonie too broad. The 

 li^ure is sli}.!htly eorreeted, the postoral (p. o.) and posterodorsal (p. d.l arms heinj^ 

 in a more upright (but unnatural) position in the specimen from wliieli the lisnre 

 has been drawn. The basal part ol the Ull postoral rod not to be seen (piilc di- 

 stinetly, that of the ])osterodorsal rod (piilc indistinil in llie specimen. '■''" ,. p. Ir. 

 posterior transverse rod. 



Plate VI. 



Fig. 1. Larva of Arbaeiid; taken pelagieally olT the .V/.ores. The postoral and posterodorsal 

 arms broken; their length must considerably surpass that shown in the figure, '^'/i- 



2. The same larva, more magnified ('"/,). The larva is in beginning metamorphosis, 

 the anterolateral and |)reoral arms are not broken. The large fenestrated i)Iate 

 at the l)ase of the jiostoral (and, less develo|jed. the posterodorsal) rods is not cha- 

 racteristic of the larval skeleton but is connected with tlie metamorphosis, p. 

 pedicellaria: p. tr. posterior transverse rod. 



3. Larva of Heliocidaris lubercitlala (Ivamk.), seen from the posterior end; showing 

 the position of the ventral (v. tr.) and dorsal transverse rods (d. tr.); p. tr. ])ostcrior 

 transverse rod; da. dorsal arch; [>. o. postoral. )). d. posterodorsal arm; p. 1. postero- 

 lateral lobe. ^"/i. 



4. Larva of Temnolrema siulpla A. Ag., 20 days old. Drawn from life; ventral view. 

 The skeleton was merely sketched in the original drawing; as it has been dissolved 

 in the prei)aration, so that the sketch could not be completed, it liad to be omitted 

 in the figure. '""/,. 



5 — 6. Young larvie of Hololhiiria n. sp. ('?), from the ventral side. P"ig. ."> represents 

 a specimen :i days old, Fig. 6 another, 8 days old. The rectum Is indiscernible. 

 The frontal area in fig. 6 probably loo narrow, due to contraction on preserv- 

 ation. '»%. 



Plate VII. 



Fig. 1. Larva of Mespilia (/lobaliis (Linn.), 1.") days old; seen from above, but in such a 

 position that the body is leaning somewhat over to the ventral side. The fact that 

 the posterodorsal arms are narrower than the postoral arms in this figure is due 

 only to the oblique position; in reality these four arms are of the same width. Drawn 

 from life. "»/,. 



2. Larva of same species, ventral view; drawn from a preserved specimen. (This ac- 

 counts for the narrowness of the postoral and posterodorsal arms as compared 

 with fig. L) Beginning metamorphosis: two pedicellaria' have appeared in the 

 posterior end. Same age as the larva represented in fig. 1. '""/,. 



.'{. Larva of Arhacia sicllala (Blv.); dorsal view. '^j\. 



A. Young larva of Li/lfcliiiiiis panamcnsis Mrtsn., ventral view; .'> days old. Drawn 

 from life. "*»/,. 



o. Young larva of J^yteihiiuis ananusiia H.L. Clark; side view; 7 days old. Drawn 

 from life. ""/j. 



Plate VIII. 



Fig. 1. Young larva of Lylechinus variegaliis (Lamk.), 2 days old. \'entral view. Drawn 

 from lite. '•»/,. 



2. Young larva of Tripiuiislcs i-snilvnltis (Leske). .'i days old. \entral view. Drawn 

 from life. =»»/,. 



3. Larva of Lylechinus anamesus H. L. Clark, 7 days old. Not yet fully formed. \'en- 

 tral view. Drawn from life. '"/,. 



4. Larva of same species, same age as fig. 3; dorsal view. Drawn from life. '"/,. 



