TUNICA TES. 61 



The chain SaJpa, before the ripening of its spermatozoa, is to be regarded as a nurse. 

 To the writer it seems tiiat these differences, apparently so marked, arc in reality 

 reconcihible ; and tliat it is jiartly a question of definition, and partly due to the fact 

 that the tissues of the individuals of tlic chain are outgrowths from the solitary form, 

 so that it is difficult to say which should be regarded as the parent of either sexual 

 element. 



The individuals of the chain Salpw are variously arranged, being placed with their 

 axis parallel or transverse to the chain, or in some intermediate position. The 

 members of the chain are held together by means of spurs extending from one to 

 anotiier. 



On our east coast a single species, /iS'«/^)a sjyinosa, (often called *S'. caboti), occurs, 

 forming chains a foot in length or even more, each chain containing two rows. 

 The body is perfectly transparent, but is frequently tinged with red or blue. At 

 times they are very abundant, filling the water for miles. 



In the trojncal seas they are more abundant, and a considerable number of sjiecies 

 have been described. 



At present, as Ave have seen, the ascidians are placed at the bottom of the verte- 

 brate series, but among the so-called worms exists a form, lialanoglos.fiis, which may 

 belong here, occupying a place below the tunicates. This view receives consideral)le 

 confirmation from the researches of Mr. Bateson on the species which lives in the 

 North Carolina waters. Unlike the previously known forms, this species does not pro- 

 duce a Tornaria larva, but develops directly into the adult by processes which recall 

 those of Amphioxus, next to be taken up. Bakmoglossus and its peculiar larva are 

 figured and described in our first volume. 



J. S. KiNGSLEY. 



