Mr. F. J. Bell on Pentastomum polyzonum. 175 



the paper justifies its title by dealing only with the anatomy 

 of the new species, of which the author gives no technical 

 zoological description. He does, however, give a figure of it ; 

 and as that figure was drawn by Mr. Ford, there is no need 

 to say that it is excellent. The parasite is represented as of the 

 natural size, i. e. 94 millims. long, and at the rings about 

 5 millims. wide ; there are, as I count them, 27 of these 

 rings. 



When we compare this figure with the description and 

 figure given by Dr. Baird (t. c. p. 22), we shall, I think, be 

 led to conclude, with Dr. Harley*, that the species are iden- 

 tical ; and we shall therefore have to regard the term multi- 

 cinctum of the latter author as synonymous with the earlier 

 term annulatiim. 



Dr. Harley concludes his paper with a reference to another 

 form, of which he provides us with an admirable figure. His 

 only account of it is a slight comparison of its characters : it 

 is " shorter and thicker, has only nineteen strong projecting 

 rings instead of twenty-seven, and its tail is conical and not 

 cleft." It was found in the collection of Dr. Sharpey, but had 

 no history connected with it. For this species Dr. Harley 

 proposed the name of polyzonum. 



As Leuckart's definition was drawn up from Harley's 

 paper without the inspection of any specimens, I add the fol- 

 lowing description, drawn up from the two specimens for- 

 warded by Mr. Dawes : — 



The specimens are two in number, both female, and re- 

 spectively 73 and 55 millims. long ; they are of a cream-white 

 colour ; and the integument is, at regular intervals, produced 

 into an encircling ridge, so that the animal is divided exter- 

 nally into a number of rings ; the general character of these 

 cannot perhaps be better defined than in the words of Diesing, 

 " cute externa in forma praeputii ;" and this is especially true 

 of the terminal division. The head is square, and measures, 

 in the larger specimen, 5 millims. either way. On its inferior 

 surface and quite at the anterior edge there are four elongated 

 slits, taking a slight direction outwards ; and each of these is 

 provided with a single largish hook, sharply recurved at its 

 extremity. The small circular dot-like mouth is about 1'5 

 millim. from the anterior edge of the head. 



Of the succeeding rings there are nineteen in both speci- 

 mens; the general width of the body at the rings is 7*5 millims.; 

 and the intervening parts are about 5 millims. wide. It is 



* u I think it probable, however, that the animal which he [Dr. 

 Baird] described is one of the same species as I have obtained speci- 

 mens of." 



13* 



