^jTunlai"'e%Tim'] I^oyttl MicTOSGopicol Socletij. 73 



broad. In a general way tlie smaller ones are placed anteriorly, and 

 the larger posteriorly ; but if a transverse section be made, various 

 sizes are found on the same level. In the substance of the wall of 

 the tube are found longitudinal smooth fibres, which are collected 

 into a bundle at its posterior extremity, and proceed backward for 

 a short distance covered only by the general parietes of the pro- 

 boscis. This forms the second portion. The smooth fibres after a 

 short course enter the third part, which is the longest. If a trans- 

 verse section be made of this part, it is found to consist of six layers 

 of striated muscular fibres, enclosing the smooth fibres above men- 

 tioned. Each layer consists of a single fibre, forming as it were a 

 complete muscle in itself. There are no tendons. The three outer 

 layers do not make the whole circuit of the proboscis, but are 

 bevelled off" and inserted into the outer covering. The three inner 

 are much smaller in diameter, and complete the circle, which their 

 extremities touch. The consequen(^e of this arrangement is that 

 the smooth fibres are not in the centre, but rather on one side. 



Longitudinally the striated fibres are arranged in close juxta- 

 position and are directed diagonally, their origin and insertion being 

 at points anterior and posterior to each other ; the layers cross each 

 other at right angles, the first going from right to left, the next 

 from left to right, and so on, the individual fibres varying in size 

 from O-005"™ to 0-032"™, the smallest forming the internal 

 layers ; they have a tendency to break up into disks and fibrillas ; 

 their shape is either round, square, or with a sinuous contour ; they 

 recall to mind the muscular fibres of insects, but the elements are 

 much larger ; the smooth fibres extend quite to the posterior 

 extremity of this portion. There is an external covering for the 

 whole proboscis ; over this part it is thin and membranous, and 

 is only seen on a transverse section, but anteriorly it is very thick, 

 and at the point where the smooth fibres enter, the third portion 

 develops a round solid knob projecting internally, whose use is 

 not apparent. If the whole structure were divided into 115 parts, 

 the first part would occupy about 38 of those parts, the second 

 part would take 7, and the third part 70. The body is tongue- 

 shaped, and marked by minute transverse rugae, and contains the 

 usual elements of this class of animal. There are no traces what- 

 ever of any digestive or generative organs ; the specimens were not 

 enclosed in any cyst, but were found free, doubled up in the tubules 

 of the liver, which being distended performed the ofiice of cyst for 

 the parasites, tlie position in which they were found having pre- 

 cluded all movement. 



On looking over the literature of the subject, I found that the 

 figure which most nearly resembled my specimen in the shape of 

 the head was that of Bothrioceijhalus Corollahts of Fiudolphi;*' 

 * 'Hlstoria Entozoorum,' Table ix., Fig. 12. 



