n7 



Stations 12, 38, 74, 100 and 297 are all of medium size, 100 — 125 mm. long, while those 

 that were taken at the Stations 306 and 312 are still considerably smaller, measuring 65 — 80 mm., 

 so that they are even not vet half as long as the male from Stat. 173. 



The examination of this collection proved in the first place that, like Pies. Ortmaiuii 

 Dofl. (H. Balss, 1. c. p. 31), also Pies. mart ia belongs to those species in which the ova- 

 bearing individu als var; considerably in lengt h, to those in which the reproductive 

 organs are already developed at a tender age, so that the animal is enabled to procreate 

 from that age until its death: not only, indeed, are the ova-bearing females from the above- 

 mentioned Stations of medium size, but the numerous egg-laden specimens from the Stations 

 306 and 312 are still quite young, being not yet half as long as the full-grown specimen from 

 Stat. 173. While the medium-sized and adult specimens, preserved in alcohol, show all the 

 same uniform straw colour, in the young individuals from the Stations 306 and 3 1 2 the first 

 to third abdominal terga are often marked with a transverse blackish or dark coloured band, 

 though a great number of them are also quite unspotted. 



The measurements revealed furthermore the fact, already suggested by Stanley Kemp 

 (l.c. p. 95), that in the indian representatives of Pies. martia the rostrum is constantly short er, 

 comparatively, than in the typical species from the Mediterranean and the East Atlantic (see 

 the Tables of measurements) : it is therefore justified to regard the indian form as a variety 

 semilaevis Bate. When the length of the body is measured from the back of the orbit to the 

 tip of the telson, the rostrum varies in ten medium-sized specimens, collected at Stat. 12, from 

 39 per cent. to 47 per cent. of the length of the body, according to Senna's measurements 

 (1. c.) in seven specimens from the Mediterranean, however, from 45 to 58 and according to 

 those of Stanley Kemp in eleven full-grown and medium-sized specimens from the coasts of 

 Ireland from 51 to 67. In the full-grown male from Stat. 173 the ratio of rostrum to body 

 (100) is even only 34. 



When the rostrum is included, its proportion to body proved to be only 25 per cent. 

 of the length of the latter in the adult male from Stat. 173, while it varied from 28 to 32 in 

 the ten medium-sized specimens from Stat. 12, in the eleven adult or medium-sized specimens, 

 mentioned by Kemp, this proportion, however, varied between 34 and 40 and in 5 medium- 

 sized specimens from the Mediterranean between 32 to 37 (Senna, 1. c). Like in most species, 

 also in Pies. martia the rostrum appears comparatively longer in younger specimens, which 

 fact is also proved by the Table: the measurements of these younger specimens are therefore 

 not comparable with those of Senna or Kemp, whose specimens were adult or of medium size. 



Unnecessary to remark that the relative length of the rostrum varies also rather much 

 in the numerous specimens of this collection. In the adult male, long 169 mm., from Stat. 173 

 the rostrum is only one-third longer than the carapace, in the specimens of medium size the 

 proportion between the length of the rostrum and the carapace varies from 1,6 t o 2,2 and in 

 the young specimens from the Stations 306 and 312 from 2,2 to 2,9, the rostrum appearing 

 in the latter sometimes almost 3-times as long as the carapace: these numbers prove again 

 that with advancing age the rostrum becomes relatively shorter. 



According to Stanley Kemp (1. c. p. 94) the rostrum is armed dorsally in the typical 



