DP. T. S. COBBOLD ON THE PARASITES OF ELEPHANTS. ^27 



very minute, and exceedingly numerous. This portion of the body does not differ in the 

 two sexes." 



With this part of Dr. Baird's description my observations generally agree ; but he 

 appears to have overlooked the four larger equidistant denticles, of which the lateral pair 

 are especially conspicuous. I examined the mouth with some care. By a little pressure 

 the buccal apparatus and narrow muscular oesophagus are well seen under a half-inch 

 objective, several abductor and adductor muscles being plainly visible through the 

 transparent skin. The buccal cavity itself is broadly cup-shaped, being armed, as 

 Baird has said, with two rows of closely set and erect denticles. I did not observe any 

 marked disparity of size, as between the two sets of teeth ; and their number is probably 

 the same. I twice counted the denticles of the outer circle, and found their number to 

 be 44 ; consequently, with the four larger teeth, the mouth cannot be armed with less 

 than 92 of these organs. The length of each tooth was about the -^s °f an mcu °nly, 

 the teeth of the inner circle alternating in position with those of the outer. 



The bursa, or hood, of the male worm is a very striking object. By reason of the 

 unusual number of rays or, rather, I should say, of ray-divisions, a correct interpretation 

 of these parts is not easy. Dr. Baird's account and that which I am about to offer are 

 scarcely reconcilable. If my account should prove the more correct, it must be remem- 

 bered that Dr. Baird had not the advantage of knowing Schneider's published views 

 respecting the typical number of parts to be recognized in this organ. It is difficult to 

 interpret the facts given in Dr. Baird's memoir, though they have evidently been 

 recorded with great care. 



" The tail of the male," says Dr. Baird, " is in the form of a membranous expansion 

 or pouch surrounding this extremity of the body, and is divided into three lobes. The 

 central lobe is the largest, and is supported by seven ribs or rays, three in the middle 

 and two at each side. The three central ribs are dichotomous, and the middle one of 

 these has its two branches sending off two or three short processes, like buds ; the two 

 others are simple. Of the lateral ribs (two on each side) the innermost one is dicho- 

 tomous, the two branches into which it is divided sending off short processes or buds ; 

 the outer rib is simple. The two lateral lobes of this caudal expansion are smaller thau 

 the central one, and are each supported by four simple ribs." 



In the right and left views (profile and oblique respectively) which I have selected for 

 general illustration of the appearances presented by the tad of the male worm, little 

 more than the points of the rays can be seen (PI. XXIII. figs. 2 & 8). As there 

 shown, nearly all the rays extend to the border of the hood, whilst some of them 

 point beyond the ordinary level of the margin, which consequently assumes a slightly 

 serrated outline. This appearance is not constant. Having only two specimens of the 

 male to examine, I found some difficulty in arriving at a true interpretation of the parts ; 

 but I believe they are correctly rendered in the accompanying scheme. It is, of course, 

 immaterial to which half of the hood-rays the description is taken to refer, since, prac- 

 tically, the arrangement and symmetry are perfect throughout. The anterior ray (a, a') 

 is dichotomous and cleft to the base. The antero-lateral ray (b) is straight and simple. 

 The middle ray (c, d) is dichotomous, cleft to the base, andthe branches incline toward 



