1861.] DR. T. S. COBBOLD's LIST OF ENTOZOA. 117 



eye is of moderate size, one-fourth of the length of tlie head, and 

 much wider than the interorbital space. The scales advance supe- 

 riorly to between the hind margin of the orbits, and inferiorly to the 

 proeorbital. None of the bones of the head are serrated ; the prse- 

 operculum has two ridges along its margins, like Apogon, but the 

 ridges are very close together. The spinous dorsal tin commences 

 somewhat nearer to the snout than to the root of the caudal ; the 

 length of the first spine is not quite one-half of that of the second, 

 which is the strongest and longest, its length being one-half of that 

 of the head ; the following spines rapidly decrease in length. The 

 soft dorsal fin is slightly continuous with the spinous, both being 

 nearly equal in height ; its anterior spine is short, although longer 

 than the last of the spinous dorsal. Caudal fin rounded, its length 

 is contained six times and a half in the total. Anal spines strong, 

 the second and third are nearly equal in length. The root of the 

 ventrals is situated behind that of the pectorals ; they do not quite 

 extend to the vent, and are as long as the pectorals. The colour 

 appears to be greenish above, each scale liaving a darker margin. 



Two specimens of this fish, the larger of which is 33 lines long, 

 were received from the Murray River, and, having been given me 

 for determination by Mr. Iloldsworth, are now deposited in the 

 British Museum Collection. 



5. List of Entozoa, including Pentastomes, from Animals 



DYING AT THE SoCIETy's MeNAGERIE, BETWEEN THE YEARS 



1857-60 INCLUSIVE, WITH Descriptions of several New 

 Species. ByT. Spencer Cobbold, M.D., F.L.S. 



(Plate XX.) 



During the interval above-mentioned I find that 122 different ani- 

 mals have been specially examined by me with reference to the pre- 

 sence or absence of Entozoa. This number of individuals represents 

 upwards of 100 distinct species, 38 of which (or, in round numbers, 

 about one-third) were found infested. Of these 38 there are 19 

 mammals, 14 birds, and 5 reptiles. The mammalia harboured 6 

 trematodcs, 8 cestodes, 5 nematodes, and 1 species of pentastome, — 

 larval and immature forms being included. The birds contained 2 

 trematodes, 6 cestodes, and 14 nematodes ; whilst the reptiles were in- 

 fested by 2 flukes, 1 tape-worm, 6 round-worms, 1 acanthocephalous 

 helminth, and 1 pentastome. Altogether I have found in 38 ver- 

 tebrate species no less than 51 different forms of Entozoa, comprising 

 10 trematodes, 15 cestodes, 23 nematodes, I acanthocephalous ento- 

 zoon, and 2 pentastomes. 



In very few instances can these parasites be said to have been the 

 entire cause of death ; but in several cases they manifestly contributed 

 to bring about that result, and in one instance their presence was 

 the sole cause of death. This was evident in a Ring-tailed Lemur 



.£k 



