4 Fishery Board for Scotland. 



formed of parallel longitAirlinal fibres. The inner layer is darker in 

 colour. It is more fragile and brittle than the outer layer ; it cracks 

 across in any direction. It is thickened at the side seams of the 

 purse, filling up the angle. In the latter its central region may be 

 lighter in colour than the rest. The inner \a,jev is, however, also 

 formed of longitudinal strite. 



Beard says that slit-like apertures are to be found on the inner side 

 of the extremities of the horns. According to this author, the chief 

 time of reproduction is in March and April, but some eggs are 

 developed and fertilised in all the other months of the year. He 

 considered that development requires nine or ten months. The rate 

 of development in the early summer months was as rapid again as in 

 winter. 



A large purse was sent from one of the Aberdeen fish -yards to the 

 Laboratory in January. It is shown in natural size in fig. 6. It was 

 evidently an abnormally big purse of R. batis. It was similar in 

 colour, and had tendrils of just about the same length as those of a 

 normal purse. It had been flattened, and the contents were broken 

 up. It was, however, possible to make out that it had contained only 

 one egg. The cB.vitj was a single large one. The ovum had been in 

 the broader half. The yellow yolk was confined to that part, but 

 some of the white yolk had been forced into the other half. The white 

 yolk, although it adheres strongly to the test of the purse, is not 

 organicallj^ connected to it. 



Eaia ciavata, L. (The Roker). — The purse of this form is shown in 

 natural size in fig. 8. When taken from the parent it is of a 

 larainarian colour. Stringy appendages were attached to the purse 

 here shown. But some purses of this species have no strings. One 

 piH'se was of the same length as the one drawn, but much narrower. 

 Beard received the purses of this form from January to June. 

 Bugnion states that the average weight of the egg of this species 

 is 30 grammes. 



Haia macitlata, Montagu. — Beard received in April a consignment 

 of purses taken from Raia maculaia. He could find no difference 

 between them and the purses of Raia ciavata. Holt & Calderwood,* 

 however, figure the purse taken from a female of this species 

 measuring 28 inches (70 cm.) in length (fig. 12). The purse 

 measured 2|- inches (6-7 cm.) x 1^ inches (4-3 cm.). The external 

 surface is smooth. 



Raia hlanda. Holt and Calderwood. — The purse taken from a female 

 46 inches (115 cm.) in length, measured, exclusive of the horns, 5^ 

 inches (13'6 cm.) x 3 inches (7'6 cm.)* (fig. 10). The external 

 surface is smooth. It is readily distinguished from the purse of 

 macidata by its greater size. There is not much difference in the 

 relative length of the horns in the two species. 



Raia microcellata, Montagu. — The purse taken from a female 34 

 inches (85 cm.) in total length, measured 3^^ to 4 inches (9 to 10 

 cm.) X 2\ inches (57 cm.)* (fig. 11). 



Raia circularis, Couch. (The Cuckoo). — The purse is seen in natural 

 size in fig. 4. Its horns are very long. When found in the sea the 

 purse is often black. Beard received the purses of this species from 

 Februaiy to June. 



*HoLT, E. W. L., and Calderwood, W. L. " Survey of Fishing Grrounds, 

 West Coast of Ireland, 1890 1891. Report on the Rarer Fishes." Five plates. 

 Trans. Boy. Dublin Society, N.S. Vol. V. Part IX. 1893-1896. 



