Miscellaneous. 187 



flatHsh ei)illu']ial ctlls, niid then a tliickor, tiMnsparont, clastic, and 

 very extensile cliitinons layer. 



From the end of the ductus cjaculatoiius to the external opening 

 of the sexual nj)])aratus wc have an uninterrupted cliitinous sac, 

 with various kinds ot cvafi;inations, folds, and thickenings. The 

 upper portion of this section of the sexual apparatus, termed tlie 

 " bulb '' hy Leuckart, is laterally compressed, and has beneath a 

 delicate external membrane very columnar epithelial cells, beneath 

 which there lies a tolerably thick layer of transparent colourless 

 chitin, upon which on each side two large chitinous plates, which 

 are fused togetlicr, are fixed. The chitin of these plates has a 

 distinctly granular structure, and the clearer and softer the chitin, 

 the more plainly are the granules visible. In the completely 

 hardened places the granules cannot be seen at all, or only indis- 

 tinctly. 



The portion of the genital sac which follows the bulb of the penis 

 is so strongly cliitini/.ed that nothing is to be seen of the epithelial 

 cells. The chitin is thickly covered with stout simple (not branched ) 

 hairs, directed inwards, which are larger and thicker at those spots 

 where there are evaginations and folds in the chitinous wall. These 

 structures have, as everyone is aware, a mechanical importance in 

 the act of coition, and have been described a thousand times, but 

 never quite correctly. The exact description of these structures is 

 out of place in a provisional communication, since too many details 

 would have to be alluded to. I will only observe that, with the 

 exception of the above-mentioned chitinous plates of the bulb of the 

 penis, we find no plates in the entire genital sac of the bee, but 

 only evaginations and folds of the chitinous wall. 



The detailed description of the genital apparatus will appear in 

 the ' Tageblatt der zoologischen Abtheilung der kais. Gesell. d. 

 Naturw. Anthropologic und Ethnographic.' — Zoologischev Anzeir/er, 

 xiv. Jahrg., ISUl, no. 370, pp. 393-390. 



On the '■' Free-sivimming Sporocysts." By M. Braitit, 

 of the Kcinigsberg i. I'r. Zoological Museum. 



The term "free-swimming sporocyst" has been applied by E. 

 Eamsay Wright * and li. Leuckart f to the single example Avhich 

 has hitherto been discovered of a certain developmental stage of a 

 Distomnm. I have observed numerous specimens in an aquarium in 

 which I had shortly before placed various freshwater snails from the 

 " bog " ('' Bruch '') near llossitten in the Kurischer Lowlands. 

 "While, however, the American species is only 1 millim. in length, 

 the specimens from this locality are as much as 6 millim. long, and 



* 'American Naturalist,' vol. xix. 188-5, pp. 310, 311. 

 t Die tliierischen I'arasiten des Menschen kc, 2 AuH. 2 Rd. pp. 102. 

 103. 



