70 DISCOVERY REPORTS 



only in small individuals 3-6 mm. in diameter, 9 were found in specimens up to ig mm. wide, 10 in 

 specimens between 5 mm. and 27 mm. The smallest specimen with as many as 16 tentacles was 

 12 mm. wide, and the same number was counted in a particularly large specimen, 30 mm. in 

 diameter. The number of tentacles most frequently met with was 12; it was found in 32 of the 

 84 specimens examined. 



D1.STRIBUTION. Pegatitha martagon was first described from the China Sea ; Bigelow records it from the 

 Maldive Islands in the Indian Ocean (1904, as P. simplex) and from numerous localities in the tropical 

 East Pacific (1909 and 1940). Recently recorded from the neighbourhood of the Canary Islands 

 (Kramp 1955). In the British Museum (Nat. Hist.), London, I found 5 specimens of P. martagon, 

 collected in 35° 00' S, 46^ 36' E, south-east of Africa, 29. iv. 1937 by A. Seligman. The Discovery 

 collections show that it is widely distributed in the tropical and subtropical Atlantic and the western 

 part of the Indian Ocean, whence it penetrates southwards into subantarctic seas, where it has a 

 circumpolar distribution. 



Pegantha laevis H. B. Bigelow 1909 

 (Plate VI, fig. 2, text-fig. 11) 



1909 Pegantha laevis Bigelow, p. 97. Pi. 16, fig. i ; PI. 20, figs. 4-6; PI. 27, figs. 1-7. 



1910 Pegantha laevis Mayer, p. 444. 

 1918 Pegantha laevis Bigelow, p. 396. 



1949 Pegantha cyanogramma Ranson, p. 13^. 



1950 Pegantha laevis Berrill, p. 301. Fig. 4N-L. 

 1955 Pegantha laevis Kramp, p. 279. 



Occurrence; Stns 100, 670, 671, 677, 701, 718, 1370, 1568. (For details of position, date, etc., see Table i, p. no.) 



Stns 1370 and 1568 are off the south-east coast of Africa, St. 701 is near the Cape Verde Islands; 

 the others are in the southern Atlantic between the Cape of Good Hope and Patagonia in the southern 

 part of South America (see chart, text-fig. 11). 



The collection gives very little information on the bathymetrical distribution of this species. 

 At St. 100, near the Cape of Good Hope, it was taken partly in the surface 5 metres, partly in hauls 

 550-450 m. and 2500-0 m. In all the other localities the nets were hauled from more or less deep 

 layers to the surface. All previous finds are from the upper layers. 



Remarks on the morphology. One of the most characteristic features of this species is the great 

 width of the peripheral canals. The umbrella is usually somewhat flattened, the surface completely 

 smooth, jelly generally rather soft. The interradial pockets with the gonads may be simple, sac-shaped 

 or bean-shaped, but when further developed they are irregularly lobed; in the largest specimen 

 observed (diam. 44 mm. St. 671) each gonad has 4-5 lobes of different sizes. The marginal lappets are 

 usually almost quadrate with rounded corners, occasionally they are somewhat pointed or pentagonal. 

 Marginal sensory clubs could only be counted in some few specimens and then only in some few of 

 their lappets; the number was sometimes five, sometimes seven. The otoporpae were usually shorter 

 than the width of the transverse portion of the peripheral canals, but sometimes a little longer. 



The peripheral canals are always very broad, especially their lateral portions along the peronia, 

 and of nearly the same width from their base towards the end of the lappet (PI. VI, fig. 2); as a rule 

 they are more than one-fourth as wide as the entire lappet, and sometimes the space between them is 

 narrower than the canals. Even badly preserved specimens may be specifically identified by this 

 character. 



Larvae, as they are described by Bigelow (1909, p. 99), were found in the peripheral canals of two 

 specimens from St. 1568, 17 mm. and 25 mm. in diameter; in these specimens no gonads were 

 developed. 



