30 



There arc also in the collection several si)eciniens of a Hemiram- 

 pfius, which is known locally by the name of ' Guard Fish.' They are 

 only half the full size, which is said to be fifteen inches. Several 

 specimens of a Diodon have all the characters ascribed to D. nycthe- 

 merus in Cuvier's monograph {Mem. du Mus., iv.). Two species of 

 Hippocampi are probably those described by White and Shaw as in- 

 habitants of Port Jackson. A ' Rock Cod' taken in the sea was too 

 much decayed for examination, the skull being all that could be 

 preserved ; and several examples of a small freshwater fish were also 

 very much injured. The species bears the local name of ' Trout,' 

 is said to have an olive colour, with small red spots, and to weigh 

 when full grown about nine ounces. It is perhaps the Galaxias 

 truttaceus of Cuvier, or an allied species. A ' Sea Cow' mentioned 

 in the list may be the Callorhynchus Tasmnnitis. A Solea of a sub- 

 orbicular form, and having a small square spot on each scale, and a 

 freshwater Anguilla, remain undescribed. 



A paper by G. Gulliver, Esq., entitled ' Notes on the Ova of the 

 Distoma hepaticum, and on certain Corpuscles obtained from the ge- 

 nera Cysticercus, was read. 



The physiology of the Common Liver- Fluke Is extremely interest- 

 ing, on account of the connection which this parasite has with a very 

 frequent and fatal disease of that useful animal the sheep. 



" If we obtain," saj'^s Mr. Gulliver, " from the bile-ducts of the 

 sheep some of the larger ova of the entozoon, and subject them to 

 careful examination, it will be found that the cxst of the ovum pre- 

 sents a very clear outline, the continuity of which is uninterrupted, 

 except at one end, where a well-marked operculum may be seen, as 

 rcjiresented in the drawing. 



" The size of these ova differs considerably ; their average length 

 is about gjoth of an inch, and their breadth ^^th. 



" The interior of the cyst is occupied by granular matter, often con- 

 tained within secondary and more delicate cysts or cellules, generally 

 of a circular figure, and occasionally having within them a third still 

 smaller cyst. The diameter of the latter is about ^ooth of an inch, 

 and of the secondary cysts yJon''^ ^^ ^"^ ^"^'^ ^^ ^ common size, 

 although their magnitude is very variable. The granules within the 

 cells or cysts also differ much in size, but they are very commonly 

 about ^^Vo^'^ ^^ ^" inch in diameter. 



" When the ova of the Distoma are compressed forcibly, the oper- 

 culum is lifted up, or even separated entirely, and the granular mat- 

 ter extruded, with its containing cells or cysts generally broken. 



" The operculum does not appear to exist in the smaller and im- 

 mature ova. The drawing No. 2. represents this in some ova ob- 

 tained from the uterus of the Fluke. 



" Whether what is commonly called the ovum of the entozoon, 

 may not be a cyst containing numerous ova within it, and furnished 

 with an operculum, to allow of their extrusion when mature, and fit 

 for propagation, appears to me to be an interesting question. At all 

 events it should be ascertained if the cysts be discharged with the 



