INTERNAL ANATOMY OF THE GAMASID.E. 303 



Between the diverticula the cornu arises ; it is smaller than in //. horridus, but of somewhat 

 similar shape, except that it is generally joined to the sacculus by a small, almost globular 

 chamber with a narrow neck. The rami are short but wide ; and the ringed tubes much 

 of the same nature as those before described, but they do not terminate exactly where 

 they reach the rami with a simple opening into the latter, as in //. horrklus ; they enter 

 the rami and continue within for a minute distance, then each ringed tube terminates in 

 a very small, almost globular enlargement within the ramus (fig. 54) ; this sphere is so 

 clear and delicate that it can only be seen under favourable circumstances and with a 

 highish power, but it certainly exists. I have not been able to determine to my own 

 satisfaction whether this and similar, or more or less similar, terminations of ringed tubes 

 iu other species are really permanent closings, or only in the nature of valves; the latter 

 is the more probable, although I have not hitherto detected any openings, but they are 

 so small and tine that proper examination is almost impossible, and I have not been able 

 to trace them in the sections. 



Lcelaps oribatoides (tig. 56) is another allied species much of the H. hirsutus type, but 

 with considerable differences. The two globular diverticula are present, but in this 

 species are smaller than the sacculus, while the central anterior diverticulum of the last 

 species is entirely absent : the cornu, however, in //. oribatoides assumes much greater 

 importance ; it is an organ containing nearly as much space as the sacculus and winds 

 over and round the lyrate organ down to the underside of the camera spermatis, where 

 it enters. The lyrate organ in this species is singular in form, the distal ends being 

 much enlarged and forming irregular hatchet-shaped pieces, which are much reflexed. 



L&laps vacua is a very small species ; in it we find a widely different development of 

 the sacculus organs (fig. 57) ; that viscus itself is a small globular sac without rami ; 

 the ringed tubes enter the sacculus itself and project within it, with a slight bulb, which 

 I do not think is closed ; the cornu is a large, more or less discoidal or ovoid body, not 

 regular in form, but considerably larger than the sacculus, to which it is joined by a long 

 fine tube, larger than the ringed tubes, but not much so ; the difference in the figure is a 

 trifle too great. This tube springs sharply from the sacculus and from the cornu, with 

 a well-marked line of demarcation ; it is shown stretched out in the figure, but m situ, 

 it winds round the other organs, and is slightly embedded in fatty and loose cellular 

 matter. The cornu lies with a portion of its substance almost embedded in the camera 

 spermatis and ovary. I could not, however, trace the entrance in this species, although 

 it probably exists ; I had not a sufficient number of specimens for investigation, and the 

 creature is very small and delicate (extreme length about - 5 mm.). 



Fig. 58 represents the sacculus and cornu of a small species very like L. vacua exter- 

 nally, and with these organs similar in principle. 



Lcelaps acuta is a smallish and very swift species, which again presents novelties in 

 the set of organs we are considering; it has an elliptical sacculus (fig. 59, sa), without 

 any rami : the ringed tubes enter the sacculus itself as in L. vacua ; they enter it on the 

 underside. The cornu in this species, instead of being a separate sac attached by a 

 long tube as in the last, is a mere short conical projection in the middle of the anterior 

 surface of the saccidus, thus being almost at right angles to the ringed tubes ; the apex 



