1917] Kiffcr-For.'iijtlt: Ascidians of Southern California 489 



proliferum IM. Edw. of Amarnuciton being, as is well known, pedun- 

 culated. And numerous species are more or less sand covered. 



The serious difficulty is in the entire absence of an atrial languet 

 and the regular 6-lobing of the orifice. But although the possession 

 of a languet is rightly regarded by most authors as one of the best 

 generic characters of Amaroucium, a comprehensive review of the 

 genus reveals the fact that while in the great majority of the species 

 the languet is distinct and large, a fairly complete series from the 

 langueted orifice to the regularly lohed type like that in our animal, 

 exi.sts. 



A. complanatum, ITertim., and A. pallidum, Herdm. are described 

 by their author (Herdman, 1891) as having the atrial languet short 

 and inconspicuous. In A. pribilovcnse Ritt. (Ritter, 1899), the 

 languet is "very variable in length, in some zooicls the siphon depart- 

 ing but slightly from the noi-mal 6-lobed condition." And finally in 

 A. anomalum. Herdm., the atrial siphon is wholly absent, judging from 

 the author's figure; the point is not mentioned in the text (Herdman, 

 1899, pi. Pel III, fig. 14). 



Nor could one expect otherwise than that a range of variety like 

 this would occur in a genus of many species when he considers the 

 abundant evidence that the atrial languet is, phylogeneticall.y speak- 

 ing, a late differentiation from the normal, evenly bordered siphon. 

 On the whole, therefore, we have thought it more warrantable to place 

 the species in this genus than to adopt the next best alternative — 

 that of establishing a new genus — a course which may be necessary at 

 some future time when a study .shall have been made of the kindi-ed 

 animals from the w^hole California coast. We have observed several 

 other closely similar ascidians from points north of Point Conception, 

 and an exhaustive study of all these may necessitate a change in the 

 present disposition of the species now under consideration. 



In concluding, for the present, these remarks on the taxonomy of 

 this species, we would point out that were the genus Sigillina to stand 

 substantially as described by Savigny, these California species would 

 probably accommodate themselves more easily to it than to any other 

 of the numerous small off-side genera of the family Synoicidae 

 (Polyclinidae). If, however, SagilHiia really belongs to the Poly- 

 citoridae (Distomidae) as is now held to be the case, there would be 

 no possibility of placing our species in this genus, for its polyelinid 

 characteristics are unequivocal. 



