228 



DE. T. S. COBBOLD ON THE PAEASITES OF ELEPHANTS. 



Fig. 1. 



Diagram of the hood and rays of Sclerostoma sipwicidi- 

 formt ( x 36 diameters i. 



each other at their points. The postero-lateral ray (d) is simple, and rather short. The 

 posterior ray is furnished with a remarkably broad base (e) ; it is tetrachotomous 

 (e to e""), its innermost branch being 

 united at the upper part to its fellow of 

 the opposite side. The innermost branch 

 gives off two rudimentary secondary 

 branches, the inner of the two necessarily 

 lying nearly parallel to that of the opposite 

 side, and therefore also parallel to the 

 intervening middle line forming the ver- 

 tical axis of the hood. As regards the 

 membrane of the bursa itself, the three 

 lobes are fairly distinct, the posterior 

 lobe being large, well marked, and slightly 

 truncated at the apex. 



If the above description be compared 

 with that given by Dr. Baird, a corre- 

 spondency may be traced here and there. 

 Thus his so-called middle ray of the cen- 

 tral lobe evidently agrees with the inner 

 division of the posterior ray in Schneider's 



system (as applied to the present species). Thus, also, the two or three bud-like processes 

 to which Baird refers must clearly be the same as those rudimentary rays observed by 

 myself, and called the outer and inner secondary branches of the innermost division of the 

 great posterior ray. Of course in attempting to reduce and describe this complicated set 

 of rays to the proper number assumed by Schneider to be typical of the strongyles, my 

 interpretation may be open to dispute. I do not think there is any important error in 

 this record, although the occurrence of such a number of separate ray-divisions in 

 any single hood is altogether outside my previous experience. 



The spicules of Sclerostoma sipunculiforme are long, equal, and remarkably narrow. 

 They measure about ^ of an inch in length, and have their points irregularly twisted, and 

 directed backwards. In their retracted state they are apt to be overlooked, although gentle 

 pressure of the covering glass will readily reveal their presence and position (PI. XXIII. 

 fig. 2). When partly exserted, their shafts protrude from a cloacal outlet immediately 

 in front of which there is a conspicuous prominence (PI. XXIII. fig. 8). Neither in Dr. 

 Baird's figures nor in his description of this worm is there any mention made of the 

 existence of the spicules. Doubtless they were retracted within their sheaths, and 

 thus escaped observation. As these organs vary remarkably in the different species 

 of strongyles infesting Elephants and other animals, no diagnosis can be considered 

 complete if all mention of their characters be omitted. 



Dr. Baird's description of the tail of the female worm agrees generally with what I 

 have observed. " It terminates," as he says, " in a rather long sharp point, which is 

 oblique in position to the body, owing to a sort of tubercle about half a line from its 



