THE SEA-SCORPION FAMILY. lol 



traces of the yolk and oil-globule have vanished. TLe breast- 

 fins are very large fan-shaped organs. A thickening (hypural) 

 beneath the notochord causes a slight upward bend of the tail. 

 A single process in the upper opercular region (hyomandibnlar) 

 indicates the pre-opercnlar armature of the adult. 



A specimen of 7'3 mm. procured south-west of the Bell Rock 

 on the 8th August, 1888, may be a post-larval example of this 

 species. The body is short and thick, the two dorsal fins are out- 

 lined, but still connected with each other and with the tail by 

 the larval fin. The caudal fin is well formed, but a trace of the 

 larval tail exists superiorly where the tip of the notochord also 

 appears. The breast-fins are large. The ventrals form minute 

 processes. The front gill-cover (pre-operculum) has about four 

 spines. The posterior occipital tubercles have spines, the pair 

 in front do not show them. No turbinal spines are yet visible. 

 The specimen is much shorter than the short-spined Cottus of 

 the same age, and the body is deep and somewhat flattened. 

 The identity of this form is still doubtful. 



The subsequent stages of this species are still in need 

 of observation. Mr Holt found a form of 10'5 mm. which he 

 doubtfully refers to it. Though it has two pairs of small 

 tubercles connected by longitudinal ridges on the top of the 

 head, it does not appear to be a young Cottus quadricornis, 

 since both turbinal and supra-orbital spines are absent, and 

 therefore Mr Holt's suggestion is probably correct, viz. that it 

 is a stage in the development of the long-spined Cottus. 



In the Irish expeditions of 1890-1891 Mr Holt took a 

 young example of 21 mm. in Jeelin harbour on the 19th May, a 

 fact which shows that the spawning-period is considerably 

 earlier on the West coast of Ireland. On the East coast of 

 Scotland this species spawns somewhat later than the short- 

 spined bull-head if the interpretation in regard to the eggs and 

 larvae, by Mr Holt and ourselves, is correct. In the recent 

 Scandinavian Fishes the spawn ing- season is stated to be the 

 end of November and in December ; Mr Cunningham again at 

 Plymouth found the period of deposition to be from January to 

 March. 



In August a specimen 44 in. long occurred at St Andrews. 



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