goluschmidt's monograph of amphioxides. 593 



somital gill-clefts which are lacking in the other two 

 species. 



In his description of Hatschek's nephridium Dr. Goldschmidt 

 records the important discovery of the presence of solenocytes 

 in this small tube, which occurs sinistrally under the noto- 

 chord, and opens into the prasoral portion of the gut. In a 

 specimen of 8 mm. it attains the considerable length of half 

 a millimetre. It is closely applied to the anterior end of the 

 aorta, so that only a thin membrane separates the two struc- 

 tures. The part of the tube in the vicinity of the orifice into 



Rhl 



Tig. 5. — A. valdivise. Section tlirough rostrum. After Gold- 

 schmidt. ITi. Lymph-canals whicli arise from the dorsal rostral 

 canal {drlc). sbrk. Subdorsal rostral canal at its point of origin from 

 the dorsal canalis communicans between the lateral rostral cavities, 

 E/i.l. (Anterior ends of cavities of first myotomes.) vrJc. Ventral 

 rostral canal. B/i.v. Ventral rostral cavity. 



the preeoral gut consists of high cubical cells. Dorsally this 

 epithelium ceases, and gives place to isolated large round 



forwards from the fin-chambers (_/.), and communicating by a canal 

 on the right side only {a.drh) with the cavity of the first myotome, 

 jlf./and M.II. First and second myotomes. sepL Septum between 

 the ventral rostral cavity and the splanchnocoel. Coe.d. Anterior 

 end of the splanchnocoel on the right side communicating with the 

 first myoccel. coe.s.lc. Anterior coelomic canal placing the splanch- 

 nocoel in communication with the first myocoil on the left side. 

 prod. Prseoral termination of the gut. p.p. Anterior and posterior 

 borders of the pra^oral pit. s/A. Sclerotome diverticulum of the 

 second myoccel. 



