130 E. A. ANDREWS. 



epidermis lined with exoskeleton that has the same shape. By 

 careful dissection this epidermis was removed in other cases as 

 a hollow mould in which the exoskeleton had fitted. 



That this thin, flat slit in the shell of Cambariis monteziunce 

 actually is used as a sperm reservoir is well proven on two speci- 

 mens that show the sperm as it was issuing out of the mouth of 

 the pocket. One of these (Fig. 10) was a dextral annulus like 

 Fig. 2. In this figure the bottom of the pocket is represented 

 by dotted parallel lines and the exoskeleton by parallel rulings. 

 The outer mouth or suture is shown as a black line. Extending 

 out from this on its middle loop is a large area covered with dots 

 and these were round, flat, clear bodies which with 6 and 2 mm. 

 objective clearly showed the characteristic central bowl of crayfish 

 spermatozoa. These sperms were issuing out of the middle loop 

 of the suture and spreading on either side over the surface of 

 the annulus where they might meet the eggs (Fig. 1). The sperm 

 seemed to be in a single layer over a considerable area, though 

 in a deeper mass where emerging from the suture. They lay flat 

 side by side and their clear outer part around the central bowl 

 suggested that they might be gliding along somewhat like a liquid 

 wetting the annulus. No radiating arms were made out, so that 

 here again the male must have succeeded in transferring the 

 sperm into the annulus without the expansion of the sperms into 

 those stars which were so often produced by the liquids used by 

 investigators as to be regarded as the only shape of the mature 

 sperm. The part played by the male must be the same as in 

 other Cambari for an examination of the first male pleopods re- 

 vealed some of these same round sperm cells issuing out of 

 the tip of the " canula " or discharging tip of that appendage, 

 which is doubtless inserted into the receptacle. 



Whether the above figured sperms were forced out at the time 

 the animals were killed, or just before, is not known, but the ap- 

 pearances are that pressure of some kind must be applied not 

 only to get the sperm into such a stiff rigid pocket (Fig. 9) but 

 also, to get it out again. In another specimen the sperm had 

 issued out of the suture all along its median as well as its middle 

 loop and this was probably the case in Fig. 10 before it was 

 examined. 



