W. G. VanJVhme — JBermuda Ascidians. 367 



sometimes in other genera of this family {LejytocUnuni, Dklenmnm), 

 but is especially conspicuous here. (Fig. 65.) 



The spicules are always small with short and often more or less 

 blunt and broken points. In some colonies they are all very minute, 

 in other specimens they vary more in size (compare fig. G4 with fig. 

 (37 both down to the same scale). The test contains vast numbers 

 of bladder-cells. 



The zooids also vary much in size in different colonies, reaching 

 1.5™™ or more in length in many cases. There are six short lobes to 

 the branchial siphon, and a rather long, somewhat forked languet 

 over the atrial orifice. There are four rows of stigmata with a 

 moderate number in each, and probably eight tentacles. 



The male reproductive organs consist of about five (the number 

 varies) sej^arate pyriform testes placed radially with the small ends 

 in the center, where the short ducts arising from them unite to form 

 the vas deferens which coils about the group in the usual manner, 

 making about five turns. The ovary lies between two of the testes 

 on the side toward the stomach, more or less covered by or included 

 in the coils of the vas deferens, except when the eggs become so 

 large that it must extend beyond these limits. 



This beautiful species is moderately common, both along the shore 

 under stones, and in deeper water on corals, sponges, etc. It was 

 obtained in Castle Harbor; Harrington Sound; and at Hungry Bay; 

 and was collected both in 1898 and 1901. The specimens contain 

 large reproductive organs and larvre, and the species would probably 

 be an unusualh^ favorable object for embryological or histological 

 investigation. 



Genus Diplosoma MacDonald, 1858. 



Colony incrusting, generally rather thin. The test is penetrated 

 bv more or less extensive 'cavities continuous with, and regarded as 

 extensions of, the common cloacal cavities, which greatly reduce the 

 amount of test substance, leaving in extreme cases little of it except 

 the thin layer bounding the colony and a thin layer about each 

 zooid, the latter being retained in position by strands or columns of 

 test substance continuous with the layer bounding the colony. 

 All the rest of the interior of the colony becomes one large cavity. 

 The extent to which this modification proceeds varies in different 

 species and to a considerable degree in different individuals. 



The test substance is gelatinous, becoming membranous on the 

 surface, and from its nature, as well as from the extensive cavities 



