Massy — The Gymnosomaious Pteropoda of the Coasts of Ireland. 233 



short thick stalks. The specimens from stations S.E. 224 and S.E. 438 agree 

 in having two lateral arms, like those of P. ciliata, each with eight suckers 

 on short, thick stalks. The median arm appears to be represented by two 

 suckers, placed side by side. These have a plain ring, without any spine, and 

 are but little larger than the largest suckers of the lateral arms, and, like 

 them, are supported by short thick stalks. It is quite possible that future 

 research may show that this description of the median arm is incomplete, as 

 the suckers are very easily detached, and their minute size renders it difficult 

 to discern them, the enterprise being further complicated by anxiety not to 

 injure the radula and hook-sacs. In the case of the specimens from the 

 other stations, all that could be noted with certainty was that sixteen or 

 eighteen suckers, very similar in size, and on short, thick stalks, were present. 

 The posterior gill seems to have distinct lateral keels. Dorsal and ventral 

 keels, if present, are very obscure. The youngest specimen is quite colour- 

 less, but a few chromatophores are present on the back of the head in most 

 of the larger examples. 



Distribution. — Near Canary Islands, 28° 2' N., 14° 17' W., a single 

 specimen (Bonnevie, 1913). 



Pneumodermopsis macrochira, Meisenheimer. 

 S.E. 470— Midwater otter trawl at 400-500 fathoms. One. 

 S.E. 503— Tow-net at 70-80 fathoms. One. 

 S.E. 1692— Midwater otter trawl at 350-0 fathoms. One. 



The specimens measure 6-8 mm. in length, and possess about thirty-five 

 small suckers, on short thick stalks, and one very large one on each of the 

 two lateral acetabuliferous appendages. The radula is composed of about 

 sixteen rows of about 6-1-6, and sixteen to twenty hooks are present in 

 each sac. The jaw resembles that of P. pauciclens, Boas. The specimens are 

 almost colourless, but purple-grey chromatophores occur on the head and 

 foot, and exhibit, when examined with a high power, the same bizarre forms 

 figured by Tesch (1904, pi. vi, fig. 143) of the chromatophores in his Clione 

 punctata. Bonnevie (1913, p. 66, figs. 35, 36) describes a specimen with "a 

 series of globe-like protuberances scattered round the base of the wings and 

 feet." He adds : — " Having seen this in only one individual, I cannot tell 

 whether it should be considered a normal phenomenon." The largest of 

 the above specimens (station S.E. 1692) exhibits similar protuberances 

 situated ventrally about half-way between fins and end of body. On open- 

 ing the skin the swelling was found to be caused by the accessory glands of 

 the reproductive organs. The gonad at posterior end of the body is spherical 

 in shape in this specimen, and smaller than the accessory glands. 



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