I. '08. 49 



extremely short. The fourth pair is scarcely as long as the 

 chela of the first pair ; the fifth is longer — about equal to the 

 carpus and chela of the first pair. The joints of these two 

 limbs have much the same proportion as in Pasiphae tarda. 

 The exopods of all five pereiofjods are well developed, and de- 

 crease in size from before backwards. 



The small endopod of the first pair of pleopods has much the 

 same form as in the three British and Irish species of Pasiphae. 

 None of the three large specimens show the secondary stylet 

 on the second pair characteristic of the male. The outer uro- 

 pods are about four times as long as wide ; apically they are 

 broadly rounded and possess a short spine on their outer mar- 

 gin behind the apex. 



Size. — The largest specimen found off the Irish coast 

 measures only 47 mm. ; one of Smith's type specimens is an 

 ovigerous female, 83 mm. in length. 



Colour in life. — The whole animal is of an evenly distributed 

 bright scarlet red colour, with very numerous darker red 

 chromatophores , which are less distinct on the flagella and on 

 the first two pairs of pereiopods. The corneal portions of the 

 eyes are reddish crimson in colour. 



Development. — According to Smith (1884), the eggs of this 

 species reach the enormous size of 4 by 5 mm. in shorter and 

 longer diameter ; in an ovigerous specimen from Canon 

 Norman's Museum (now in the British Museum) they are 

 hardly as large as this, measuring 3 by 3' 7 mm. 



On two or three occasions larval forms of rather unusual 

 appearance have been found off the Irish coast ; these may 

 undoubtedly be referred to P. sulcatifrons . Although only a 

 few specimens were obtained, a number of stages are repre- 

 sented, the largest of which are clearly specifically identical 

 with post-larval specimens of this species found in the same 

 and in other hauls. 



The smallest example in the collection measures only 

 8' 5 mm. This specimen is, unfortunately, not in good con- 

 dition, and cannot be described in detail. It shows, how^ever, 

 that at this stage the rostrum 'is represented only by a 

 minute point, the eyestalks are extremely short and almost in- 

 visible in dorsal view, while the antennules are merely formless 

 lobes. The antennal scales are present, but show no trace of 

 the spine at the outer distal angle, the flagella being only about 

 one-third the length of the scale. Three pairs of maxillipedes 

 and the first two pairs of periopods are evident, the remaining 

 pairs of the latter being represented merely by buds. No gills 

 could be observed, and neither pleopods nor uropods are de- 

 veloped. The telson is laminar (fig. 3), with an emarginate 

 apex, furni-shed apparently with six pairs of setae. 



In the same haul (S.E. 231) with this small specimen are 

 two others, measuring about 13'5 and 14 mm. This stage 

 (figs. 4 and 5), with its swollen carapace and very broadly 

 rounded telson, presents a peculiar and very distinct appear- 



