CATALOGUE OP TUNICATA. 



13 



The nerve ganglion is placed only 1 cm. behind the dorsal tubercle, 

 and the whole space between them is occupied by the very large neural 

 gland, which has many complicated openings into the atrial cavity. 



The locality is Port Jackson. Half a dozen specimens. 



This large and very solid species approaches in its characters the genus 

 Pachychlcena, which was formed (as a sub-genus originally) for the recep- 

 tion of three "Challenger" species, which differed from Ascidia in their very 

 massive cartilaginous tests. These three species were, one from Simon's 

 Bay, Cape of Good Hope, and the other two from Bass' Strait, Australia, 

 at a depth of 38 to 40 fathoms. The present species, in the condition of 

 the test, is intermediate between the ordinary Ascidia and these species 

 of Pachychlcena, consequently I now feel inclined to relinquish the latter 

 genus. 



This large species is undoubtedly new to science. I have examined 

 the following specimens : three typical examples (A, B, C) and one 

 (D) of much darker colour which might be placed as a variety, also 3 

 additional specimens (E, F, G) which were in the original collection sent 

 to the London Fisheries Exhibition of 1883. The sizes are as follows: 



