STYELOPSIS. 129 



earlier that on which Alder published Gi/ntlwt 

 the later that of his death. They do not give any 

 reason for suggesting the removal of the species from 

 Gt/nthia or Styela, merely leaving a blank space for a 

 new generic name. 



It was not until 1882 that a similar view was first 

 published, Traustedt in that year founding the genus 

 Sti/elopsis for the single species Ascidia grossularia 

 Van Ben., which in 1848 Forbes and Hanley had 

 removed to the genus Gt/nthia. Its affinities are more 

 \vith Sti/ela than with G until in, and Traustedt distin- 

 guished it from Stijela by the presence of only one 

 plait in the branchial sac, which he says is on the 

 right side; the genital organs also only being deve- 

 loped on the right side. His right side, it should be 

 understood, is Alder and Hancock's left side. 



Traustedt' s definition of these genera, in ' Vidensk. 

 Medd. Kjobenhaven,' 1882 (vol. dated 1883), p. 115, 

 may be thus translated : 



Styela. Branchial sac with four folds on the left 

 side (right, A. & H.) ; genital organs developed on 

 both sides. 



Styelopsis. Branchial sac with only one fold, on the 

 right side (left, A.^& H.) ; genital organs only deve- 

 loped on the right-side (left, A. & H.). 



The Editor has deemed a departure from his rule 

 not to include any observation of later date than 1870 



to be unavoidable with this erenus.l 



~ j 



1 . [Styelopsis] grossularia (Van Beneden) Traustedt. 

 (Plate XLVI, figs. 1-4.) 



Ascidia rustica jun. 0. F. MULLEK Zool. Danica, I [1788] 



p. 14 (pars),p\. xv, ff. 1,2. 

 [Ascidia rustica JAMESON in Mem. Wernerian Soc. I (1811), 



p. 556; PENNANT Brit. Zool. ed. 5, IV (1812), p. 100; 



(Anon.) Encycl. Perth, ed. 2 (1816), p. 597, pi. xiii, f. 9 ; 



THOMPSON in Ann. Nat. Hist. (1) V (1840), p. 94; 



(?) JOHNSTON Introd. Conch. (1850), p. 297.] 

 n. 9 



