440 



DR S. F. HARMER AND DR W. G. RIDEWOOD ON THE 



(Ofij RIDEWOOH, W. <-}., "A New Species of Gepltalodiscus (V. i/i/c/iri.-fi) from the Cape Seas," Marine 



Iiicesfii/ii/iniig, South Africa, iv., Cape Town, 1906, pp. 173-192, three plates and five text-figures. 

 (07 ] > ' Pterobranehia : Gephalodiscus," National Antarctic Kfj>e<Iition : Natural History, vol. ii., 



London [Brit. Mus.], 1907, pp. 1-67, seven plates and seventeen text-figures. 

 (U7-i "On the Development of the Plumes in Buds of O/////t//.svMs," Quart. Journ. Micr. S<-i., 



N.S., li., 1907, pp. 221-252, eleven text-figures. 

 (12) - - "On Specimens of Cephalodiscus nigrescens supposed to have been dredged in 1841 or 1842," 



Ann. l\Ia<j. Nat. Hist. (8), x., Nov. 1912, pp. 550-555, one text-figure. 

 (05) SCHEPOTIEFF, A., "Zur Organisation von Cephalodiscus" Bergens Museums Aarbog, 1905, No. 8, 



pp. 20, two plates. 

 (07) - - "Die Pterobranchier : Anatomie von G'ephalotltscHx," Zoo/. Jahrb., Ahth. fur Anat., xxiv., 1907, 



pp. 553-608, eleven plates. 

 (ii" "Die Pterobranchier: Knospungsprozess von GephalinU^-ua, und vergleichend-anatomischer Teil," 



Zfujl. Jalirb., Alitli. fiir Anat., xxv., 1908, pp. 405-491, four plates. 

 (09) "Die Pterobranchier des Indischen Ozeans," Zool. Jalirli., A/>tl/. fiir SystematiJc, xxviii., 4, 1909, 



p]i. 129-445, two plates. 

 (12) SPBSGEL, .T. W., "Pterobranehia," in Handwilrterbncli iJ*r Naiurwissenschaften (Korschelt and others), 



vii., 1912. 



LIST OF REFERENCE-LETTERS. 



an., anus. 



b.c. 1 , proboscis-cavity. 

 b.c.-, collar-cavity. 

 b.c.~a., anterior dorsal horn of collar-cavity. 



/t.i-. 3 , metasomatic cavity. 

 b.c. 3 b., part of metasomatic cavity in loop of ali- 



mentary canal. 

 c.c., collar-canal. 



c.c.i., internal opening of collar-canal. 

 c.n.s., central nervous system. 

 i?. in.-, dorsal mesentery of collar. 

 rl m. 3 , dorsal mesentery of metasome. 

 ;/..-., gill-slit. 

 int., intestine. 

 L^-L. 9 , left arms. 

 l.n., lateral nerve. 

 m., mouth. 

 ins., longitudinal muscles of metasome. 



7H-/I., notochord. 

 71. f., nerve-tract. 



op., operculum or postural lamella. 

 fi/i./., left lobe of operculum. 

 op.r., right lobe of operculum. 

 op.i-ec., recess at base of operculum. 



//., proboscis. 

 per., peristome. 

 I'll., pharynx. 

 p.p., proboscis-pore. 



?., rectum. 

 R^-R.'-', right arms. 



*/., stalk. 

 stom., stomach. 



t., testis. 

 f.l., left testis. 

 t.r., right testis. 

 i:m.-, ventral mesentery of collar. 



(ROY. 8OC. EDIN. TRANS., VOL. XLIX., 5(54.) 



