10 Fishery Board for Scotland. 



No hairs were made out on the dorsal spine nor on the hind edge of the 

 carapace. A hair is present on the carapace on either side of the base of 

 the dorsal spine. The latei'al spine is slender, straight and longish 

 (fig. 49). The " branchiostegal tooth " was present {hrst., fig. 4). 



The antenna consists of two branches ; the longer is serrated, the short 

 branch bears two hairs (fig. 82). In some later Zoese the difierence in 

 size between the two branches was not so marked as in this stage. The 

 serrated branch remains the longer. 



The abdomen is seen in fig. 45. The edges of the third, fourth, and 

 fifth segments are serrated. The end of the gut was everted in a number 

 of the Zoese as here shown. The studs are present on the second and 

 third segments. 



The telson (fig. 47) closely resembles that of holsatus. The serrated 

 spines end in fine bare needle-like tips. The rest of the spine is elaborately 

 serrated. Sometimes it appears as if the relative lengths of these serrated 

 spines might be of some diagnostic value. But where two spines appear 

 to be of difi'erent lengths it may happen that they are not lying in the 

 same plane. In a moulted skin of this stage the middle spine of each lot 

 of three was longer than the spine on either side of it. The drawing of 

 the telson of this stage (fig. 47) does not, however, show this. 



A plankton I. Zoea cast into a II. Zoea. 



II. Zoea, fig. 36; Abdomen, figs. 35, 37; Telson, fig. 33. 



Three little hairs were visible on the dorsal spine, but none were made 

 out on the free edge of the carapace. The exopodites of the first and 

 second maxillipedes had each six setae. The cast from which it came had 

 four setse on the exopodites. 



The toothed edges of the second, third, fourth, and fifth abdominal 

 segments are prominent. The little stud was not made out on the third 

 segment, nor could I see it in the cast skins of two specimens of I. Zoea. 



In fig. 35 the abdomen is shown obliquely; the ventral integument of 

 the second segment is reflected. 



The telson is shown in fig. 33. It is twisted a little. There are only 

 two teeth present on the prong of the telson, that is one less than was 

 shown in the moulted skin (I. Zoea) from which this specimen came. The 

 middle long spine on each side of the fork is evidently a little longer than 

 the two others. 



///. Zoea, fig. 43; Abdomen, fig. 32; Telson, fig. 42. 



The first and second maxillipedes have eight setse on the exopodites. 

 The antenna has now three branches. The developing third maxillipede 

 and the pereiopods are easily seen in this stage. There are three hairs at 

 least on the free edge of the carapace. 



The prolongations of the sides of the abdominal segments are now 

 prominently spinous (fig. 32). 



The telson had two new serrated hairs; they are very small and situated 

 in the fork (fig. 42). The middle long spine on each side was longer than 

 the spines on either side of it. 



A III. Zoea cast into a lY. Zoea. 



IV. Zoea, fig. 46 ; Abdomen, fig. 30 ; Telson, fig. 48. 



Three little hairs were present on the dorsal spine. Four hairs were 

 seen on the edge of the carapace. 



