Ou tlie Life-History of tlie Sbauny (Blenuius pliolis L.). 



369 



weeds among-st whicli they live. As a variety auother example 

 from a pool near liigli water mark was of a dull greeu tliroughout. 



The exterual parts of tlie female are distinguislied from tbose 

 of the male by the sliorter distauce between tbe vent and the first 

 ray of tbe anal, by tbe large, low cone of tbe genital papilla witb its 

 Wide cresceutie aperture posteriorly and tbe small urinary papilla im- 

 mediately bebind it. A conical pigmented Aap of skin (witb corru- 

 gations rurming to a median groove in many preparatious) lies close 

 bebind, and apparently Supports tbe first anal ray, but it is a purely 

 cutaneous structure. 



Tbe advanced ovaries occupy a large area on eacb side from tbe 

 pectorals to tbe vent, and tbe size of tbe eggs is comparatively great. 

 Tbe transverse diameter of tbe ovaries is greatest dorsally, and pos- 

 teriorly the Organs are somewbat tapered. In transverse section a 

 Single longitndinal Chamber occars — leading posteriorly to a bare 

 portion of tbe ovarian wall in tbe mid-dorsal region and which is 

 continuous witb the genital aperture. In tbis region tbe wall of the 

 oviduct (that is tbe narrower end of tbe ovary) on eacb side is marked 

 by longitndinal folds and soon both imite to form tbe common Channel 



— also marked by five longitudinal creases — in front of tbe ex- 

 ternal opening. Tbe ovary — in longitudinal section — forms a 

 long sheet (externally invested by its proper membrane) and tbickly 

 covered witb ova arranged in a somewbat irregulär series of trans- 

 verse lamellse, which, bowever, readily form longitudinal furrows. Tbe 

 inner wall of the organ is more massive, and is covered witb deep 

 folds of ovigerous lamell^e which also are mainly transverse in arran- 

 gement, but readily form longitudinal furrows bere and tbere especially 

 anteriorly. It would appear, therefore, that tbis arrangement of folds 



— all conducting to the central fissure — would conduce to tbe 

 rapid and safe expulsion of tbe eggs — tbe muscles of tbe body- 

 wall and tbe fibres towards tbe termination of the oviduct also aiding 

 in their extrusion. Tbe urinary papilla, sometimes witb a central 

 dimple so as to be sligbtly bifid, lies immediately bebind the crescentic 

 Upper margin of the genital opening, and in old specimens, as men- 

 tioned, a groove witb lateral furrows leads from it to the Aap in front 

 of tbe anal fin. 



Few previous autbors seem to bave noted the exact arrangement 

 of tbe external parts in the male. Tbe autbors of the » Scaudinaviau 

 Fisbes«, bowever, observe »In one of tbe males we bave examined, 

 we found at the beginning of tbe anal fin a vesiculate dermal 



Zeitschrift f. wissenscli. Zoologie. LXXXII. Bd. 24 



