234 Scientific Proceedings, Royal Dublin Society. 



Distribution. — Southern part of Atlantic and Indian Oceans (Meisen- 

 heinier, 1905). Ten stations in the North Atlantic, extending from the 

 latitude between Bermuda and the west coast of Morocco to 48° 29' N., 

 13° 25' W. (Bonnevie, 1913). 



Pneumodermopsis oligocotyla, sp. n. 

 (Plate VIII, fig. 1.) 

 S.E. 197— Tow-net at ca. 300 fathoms. One. 

 S.R. 302— Midwater otter trawl at 300-350 fathoms. One. 



Body narrow (fig. Ia), with two ciliated bands ; foot with moderately 

 long posterior lobe, without a tubercle. Neither lateral nor posterior gill 

 discernible ; but both specimens are much contracted. Length, 4-5 mm. 

 Two very large suckers, with circular aperture, and on short, thick stalks, 

 are placed directly on the ventral wall of the buccal cavity. Badula, 6-1-6 

 (fig. Ib); median tooth, with three denticles, the central being the smallest. 

 Lateral teeth very long, with broad bases. Jaw of the type figured by 

 Meisenheimer (1905, pi. xxvii, fig. 13) for his Schizobrachmm polycotylum ; the 

 separate spines resemble minute claws (fig. lc). Hooks (fig. Id) short and 

 hollow, measuring one-third to one-quarter the length of the lateral teeth ; 

 about forty in each sac. Skin unpigmented. Proboscis very transparent, 

 with dermal glands forming raised white spots. 



Spongeobranchaea polycotyla, sp. n. 

 (Plate VIII, fig. 2.) 



S.E. 654— Midwater otter trawl at 450-500 fathoms. One. 



Body somewhat rounded (PI. viii, fig. 2a) ; fins wide at base, not 

 much expanded, rounded distally ; foot with a very long posterior lobe. 

 Shape and number of sucker-bearing appendages unknown. About 30 

 moderately large suckers, on long, narrow stalks, and at least 250 much 

 smaller, also with long, narrow stalks, are present, the larger suckers being 

 about six times the size of the smaller (fig. 2d). From the position which 

 the large suckers have taken on the slide on which they are mounted, it 

 seems probable that they occupied the distal end of the appendages. Fine 

 longitudinal striae, which are probably muscle fibres, are present on all. 

 Radula, 5-1-5 or 6-1-6 (fig. 2b). Median tooth broad, with three equal- 

 sized denticles, and closely resembling Boas's figure (1886, pi. viii, fig. 120) of 

 the median tooth in Spongeobranchaea australis, d'Orb. Lateral teeth much 

 like those figured by Boas (op. cit., fig. 116) for those of Pneumodermopsis 

 ciliata (Ggbr.), except that the outermost is smaller in proportion to the 

 rest of the present species. Hooks (fig. 2e) varying in length, the longest 



