NARRATIVE OF THE CRUISE. 



163 



" Among the Ascidiae Simplices, the most important new forms constitute a small 

 group of pedunculated Cynthiidae, apparently confined to deep water, and characterised by 

 several striking peculiarities. They are more nearly allied to Boltenia than to any other 

 previously known genus, and have been placed in two closely related new genera — 

 Culeolus (see fig. 05) and Fungalus, the former containing six species and the latter one. 

 Their most important morphological feature is the very remarkable condition of the 

 branchial sac, which is simplified, apparently, by the total absence of the system of fine 

 vessels 



interstigmatic 



the result being that the large meshes are not divided into 



Fig. 65. — Culeolus wyville-lhomsoni, Herdman. Seen from the left side ; natural size. 



stigmata, as they are in a typical Simple Ascidian (see fig. 6G). In Culeolus 

 the branchial sac is strengthened by the development in the walls of the vessels of a 

 system of rather gracefully branched and curved calcareous spicules, marked internally 

 by a series of 'contour' lines. 1 These are quite different in appearance from the 

 fusiform echinated spicules found in Cynthia pallida, Heller, and in the two new 

 species, Cynthia complanata and Cynthia papktemis. Another noteworthy feature in 

 the anatomy of the genus Culeolus is the condition of the blood-vessels of the test in 



( » Zool. Chall. Exp., part xrii. p. 95, 18S2. 



