On the Nest and Development of Gastrosteus spinachia. 487 



ample caught at St. Andrews was a mass consisting of a 

 number of herrings, "small" whitings, and haddocks. 



EXPLANATION OF PLATE XIII. 



Fig. 1. Mature ovum of Callionymus lyra, L., somewliat darkly shaded, 

 and slightly altered (from keeping) inferiorly. Magnified. 



Fig. 2, Honeycomb-like arrangement of the surface of the same. More 

 highly magnified. 



Fig. 3. Immature egg of the same from the ovary. Magnified. 



Fig. 4. Section of an immature ovum in the ovary. The areolated super- 

 ficial layer of the zona radiata presents a confused appearance 

 externally, from collapse in mounting. 



Fig. 5. Young example of Staurocephalus Siberti, n. sp. The eyes are 

 absent in this example. Enlarged. 



Fig. 6. Dental apparatus of the foregoing. X 90 diam. 



Fig. 7. Dorsal bristle of the same. X 350 diam. 



Fig.S. Ventral bristle, x 350 diam. 



Fig. 9. Stem of Ttibidaria indivisa with crustacean nests (a,a) and filamen- 

 tous processes {b, b) attached to the chitinous periderm. About 

 natural size. 



Fig. 10. Structures resembling ova attached to a fragment of willow. 

 Slightly enlarged. 



XL VIII. — On the Nest and Development of GrSLStrosteus spina- 

 chia at the St. Andrews Marme Laboratory/. Bj Edward 

 E. Prince. 



[Plate XIV.] 



A COMMUNICATION to the Biological Section of the British 

 Association at its recent meeting embodied certain observa- 

 tions made during the past summer at the St. Andrews 

 Marine Laboratory^ and of this the present paper is an ampli- 

 fication. Gastrosteus spinachia, amongst the smaller Tele- 

 osteans occurring upon our coasts, is a verj common though a 

 highly interesting form. Various authors, Kupfer, Ransom, 

 Mobius, and others, have treated of this or the allied fresh- 

 water species ; but the notices of the nidification, development, 

 &c. of the marine form are very fragmentary and incomplete. 



During the summer of 1885 a large number of the nests of 

 the fifteen- spined stickleback have been examined in the St. 

 Andrews laboratory ; the process of building has been 

 watched and the early stages of development studied. 



Towards the latter end of April and during the months of 

 May and June these nests may be found in sheltered rock- 

 pools, between tide-limits, and generally some distance from 

 low-water mark, so that, as Dr. Day observes, ^' they may be 

 left uncovered for two or three hours at a time."* They 

 * Hist, of Brit. Fishes, p. 248. 



