l66 JOURNAL Ot^ CONCHOLOGY, VOL. I4, NO. 6, APRIL, I914. 



but the extent to which this cliaracter is developed varies a good deal 

 in both series : it was, however, always present in some degree. 



As regards the generative system the following points were noted : 

 (a) the ovotestis was rather darkly pigmented in some speci- 

 mens of both forms and more frequently so in " lieripensis " than 

 in caper at a : 



(h) the vesicula seminalis was generally quite dark, and not 

 seldom practically black, in both forms, and the pigmentation was 

 better developed in ^' heripensis" than in caperata : 



(c) the albumen gland and oviduct tended to be more ample 

 and voluminous in 'Wie ripens is": 



(d) the mucous glands in both species were primarily four in 

 number, and each usually divided into two terminal branches ; in 

 rare cases, however, there was no division and in others three 

 terminal branches arose from one stalk ; the total number of 

 branches found varied from 7 to 1 1 and no difference between the 

 two forms could be made out in this respect : 



(e) the duct of the spermatheca was darkly pigmented in 

 " /le ripens is," free from pigment in caperata : 



(/) the neck of the dart sac was free from pigment in caperata 

 whereas in '' heripensis" it was diffusely pigmented with a special 

 concentration into two small oval patches on the lower side : 



{g) the darts of both forms were of the simple type and 

 corresponded with Ashford's classical description^; they were 

 distinctly larger in caperata than in ^^ heripensis^' the average 

 measurements being about 3^ mm. as against 2^ mm. ] for caperata 

 Ashford gives from 2| to 3I mm. long. 



It is not very easy to appraise the value of these various points of 

 difference. The pigmentation of the ovotestis and vesicula seminalis 

 was inconstant, and the difference in size in the albumen gland, ovi- 

 duct and dart may well be due to differences in sexual activitj^, 

 though the dart is probably worth further investigation, especially as 

 the ''^ lieripensis'^ were on the whole distinctly larger than i\\Q caperata. 

 The black or grey pigmentation of the duct of the spermatheca and 

 the neck of the dart sac were, however, more definite distinctions ; 

 in these regions the caperata were quite unpigmented and, though the 

 degree varied in different specimens, in " lieripensis " it could always 

 be described as dark. The pigment was ascertained to occur right 

 through the wall in each case, and was not confined, as such coloura- 

 tions not infrequently are, to a connective-tissue sheath on the surface. 



I Journal of Condi., vol. iv. (1SS4), p. 131, and plate v. Ashford's figure of the genitalia in 

 crt/i;;-a/(i shows 7 or S primary branches of the mucous gland; the arrangement was different 

 in our specimens. 



