g4 MR. F. E. BEDDAKD ON AN ANNELID [Feb. 5, 



being hollow ; so far at any rate " hypodermic impregnation" is im- 

 probable. The accompanying drawing (text-fig. 10) illustrates the 

 form of the spermatophore, whose structure I have also investigated 

 by transverse sections. Above the stalk it swells out into an oval 

 cup which is, roughly, of about the same length as the stalk. 1 his 

 narroATs rapidly to form a short tube, which appears to be open at 

 the free end. The thickness of the walls of this— the sperm-holding 

 part of the spermatophore— are much thicker below and diminish 

 oradually towards the free tubular extremity of the structure. This 

 part of the spermatophore, as shown in the drawing, does not look 

 as if continuous with the stalk ; a slight prolongation of the latter 

 seems to embrace it. The deeply staining contents of the cup 

 appear to be spermatozoa, but their condition of preservation is 

 not sufficiently good to show histological details. 



Text-fig. 10. 



Spermatophore oi Bothrioneuron iris in situ. 



Integumental vascular netiuo)'k. — A striking feature of the other 

 two species of this genus is the existence of an integumental 

 network of blood-capillaries. This was so easily to be seen in 

 the examples of Bothrioneuron americanum w'hich I examined, that 

 I have some confidence in stating that a vascular integument 

 is not to be found in Bothrioneuron iris. I have examined ten 

 or a dozen specimens in glycerine with and without treatment 

 by potash, and I can find no trace of blood-capillaries in the 

 skin. It occurred to me of course that the posterior end of 



