255 



Fig. 5. Young larva of Trii>nruxtrs i/mlilla (Linn.), 15 days old. Dorsal view. The skeleton 



has been dissolved. --" ,. 



ft. Same as Fig. .">: side view. --" ,. s. c. suboral cavity. 

 7. Larva probably belonging lo 7'<uo/<;ii i/.siY.v mxnix (Ag. I. Not yet fully formed. 



Slightly distorted. Ventral view. "" ,. 



5. Young larva of 'l'ii.ini>iiriixli-x i>ilrliix (Lamk.). ii days old. Yenlral view. I90 /i- 



Plate IX. 



Fig. 1. Young larva of Slrongylocentrotus /rancixcunnx (A. Ag.). I days old. Dorsal view. 



150 ' 



Iv 



2. Larva of same species, 8 days old; ventral view. 150 /|. 



3. 1(1 days old; side view. 150 / 1 . 



1. Fully developed larva of Struiii/i/lnri'iitrotux friinrixciiniix. taken pelagically. Drawn 

 from a preserved si)eeimen. The course of I he ciliated band along the sides not 

 quite distinct in the specimen. la " ,. 



.">. Larva of Strongylocenlrotus pulcherrimus (A. Ag.i, I weeks old. Ventral view. -""/,. 

 Figures 1 H and ."> drawn from life. 



Plate X. 



Fig. 1. Young larva of Ei>i : <-liinux i-hlnriiliriix (Yal.). II clays old. Yenlral view. "" ,. 



2. More advanced larva of same species. H weeks old. Dorsal view. "" ,. 



3. Fully developed larva of same species; nearly "> weeks old. Ventral view. 11 " ,. 

 4 5. Two abnormal young larv;e of Ei'i'diiinix rhlurolicux. '"' ,. 



6. Nearly fully develo]>ed larva of Tfmii<>i>li-iirns lon-umtilii-iix (Klein): ventral view. 

 9 days old. Drawn from life. ""' ,. 



7. Fully developed larva of Anichnnitlfx i>lw<-nta (L.). 7 clays old. Yenlral view. " /i- 



Plate XI. 



Fig. 1. Young larva of Ilcliociilaria ItiberrnUitu (Lamk.), 6 days old. Dorsal view. 225 /i- 

 2. Fully formed larva of same species, f> weeks old. Yentral view. In the posterior 



end a pedicellaria has appeared: a muscle is seen connecting the lower ends of the 



postoral rods. Drawn from life. ' '" ,. 

 .'?. Larva of Temnopleurid, species c. Slightly restored. The I rue shape of I he epaulets 



not to be ascertained. ls %. 



1. Larva of Echinobrixsiix (Oligopodia) rerenx (M. Kdw.). I days old: ventral view. lr>5 /,. 



5. Larva of same species, 10 days old: ventral view. " 1S ,. 



Plate XII. 



Fig. 1. Larva of Echinnmrlru liicunlrr (Linn.). 7 days old: dorsal view. The body skeleton 

 has begun to be absorbed. Drawn from life. Showing the nervous system (the 

 oblique line on the anal area, at the base of the postoral arms). --" ,. 



2. Larva of Echinumrlra oblonya (Hlv.), 12 days old; side view. Body skeleton partly 

 dissolved. 200 /i- 



:i. Larva of same species, same age; ventral view. The skeleton has been omitted 

 in the figure., being partly dissolved so thai a correct drawing ol it could not lie' 

 made. (Comp. fig. 2). -"" ,. 

 I. Larva of C.olitbocenlrolns ulruliix (Linn.), 12 days old: side view. 200 / 1 . 



">. Larva of same species, same age: ventral view. Skeleton dissolved. Drawing from 

 a preserved specimen, combined with a sketch from life. 2ou , i 1 . 



6. Young larva of TeniniiiiU'iiriix lorrunwlii-iix. 2'J hours olcj : ventral view. The ciliated 

 band rather loo distinct in the figure. - 20 /i- 



Plate XIII. 



Fig. 1. Ki-liinnpliilriis Iraiisi'rrxns, species c. Yentral view. S5 /,. 



2. a. Slightly corrected, the postoral 



band having been shown in what is evidently its normal place, not in the place 

 w he' re it is seen in the specimen, below I lie- end of I he' ventral transverse rods. ' ' ,. 



