On the Crustacea of St. Andrews. 337 



membrane (fig. 34, ee), while the whole of the inner part of 

 the skeleton was imbedded in sarcode charged with minute 

 cells and granules (fig. 34, bb) 7 among which could be per- 

 fectly distinguished the monociliated spongozoa, isolated (pro- 

 bably from the force used in tearing the specimen to pieces for 

 examination), and in the aggregated globular forms of the 

 ampullaceous sacs of the species (fig. 36, c, d, g), both of which 

 corresponded in appearance and measurement with the like in 

 the parent sponge, which had been previously examined, 

 measured, and sketched for this reference, and may be found 

 among the illustrations (PI. XXI. fig. 23). 



Thus the sponge-ovule, from its first appearance to its final 

 development into the perfect sponge, had been completely 

 traced ; and thus its apparently chaotic mass had passed into 

 definite forms by that mysterious power whose manifestations 

 only we can comprehend. 



[To be continued.] 



XL. — On the Invertebrate Marine Fauna and Fishes of 

 St. Andrews. By W. C. M'Intosh. 



[Continued from p. 274.] 



Class CRUSTACEA. 



• Order Podophthalmata. 



The stalk-eyed Crustacea of St. Andrews are chiefly north- 

 ern in type ; and though the species are not numerous, many 

 are very plentifully represented. The most important forms 

 here, as elsewhere, are the edible crab and the lobster. Both 

 are caught in considerable numbers along the border of the 

 rocks by means of the ordinary crab-pots, which are generally 

 baited with fragments of grey gurnards and other fishes of 

 little value. The most successful ground is off the East 

 Rocks, though a very large lobster in the Museum of the 

 University was procured to the north of the West Rocks. 

 Some of the fishermen have an idea that if a lobster enters 

 a trap first, none of the edible crabs will venture beside it, 

 whereas a lobster will invade the crab-pot though a dozen of 

 the former are already there. Constant attacks seem to have 

 diminished the numbers of both species, and especially of the 

 lobster. I have never seen any of the latter between tide- 

 marks ; but young edible crabs are common under ledges and 

 stones, and even in the sand at low water, their presence in 



