1899] THE PLYMOUTH LABORATORY 99 



A. silus in a southerly direction ; the specimen is now in the British 

 Museum. Other occurrences recorded in this number are: — The 

 Gobiid fish, Callionymus maculatus, near Plymouth ; the Teleostean, 

 Phrynorhombus uuimaculatiis, four miles S. of Plymouth Mewstone ; 

 the Gadid fish, Motella cimbria, from the stomach of a hake in the 

 Bristol Channel ; Sepia elegans, on trawling-grounds inside the Eddy- 

 stone ; Mi/sis longicomis, in Start Bay, S. Devon, not previously known 

 outside the Mediterranean ; Mysidopsis angusta, from the same locality, 

 previously not farther S. than the Dogger Bank, but lately also re- 

 corded by A. 0. Walker from Valencia Harbour, on the west coast of 

 Ireland. 



Colours of Cowries. 



To Knowledge for December, Mr. E. Lydekker contributes an article 

 upon the colours of cowries, illustrated by a full-page photographic 

 plate. The interesting way in which the shells under consideration 

 change during their growth from a thin-lipped form with a spire, as 

 well shown by a series of skiagraphs in Science Gossip for June of last 

 year, is briefly touched upon ; while the alterations in colour, rendered 

 so easy by the hiding of the older by the more recently formed whorls 

 and the application of pearly matter to the outside of the latter, is 

 discussed in some detail. 



Mr. Lydekker is unable to throw any new light upon the object 

 served by the colouring of adult cowries, nor does he suggest why 

 the dark longitudinal bandings (which he calls transverse) of immature 

 shells, presumably primitive and laid down by the edge of the mantle, 

 should often be replaced by spots or uniform pigmentation derived 

 from the pallial surface. 



Nevertheless, the remarks show that many interesting problems 

 remain to justify a further study of cowries, and the paper affords a 

 useful illustration of the more striking types of coloration. Perhaps 

 the most striking of the spotted series is not dwelt upon, to wit, the 

 form with, for instance, a brown ground colour broken by white spots, the 

 larger of which in turn have a very dark brown dot on their centre. 



The plate would have been better entitled the markings of cowries 

 seeing that it is not coloured, and it is hoped that it will not be taken 

 as the best that photography can do for the conchologist. One is 

 constrained to say conchologist, for the article ends with an uncalled 

 for outburst against the biological method of studying molluscs. At 

 the beginning of the change for the better about which Mr. Lydekker 

 is not correctly informed, attention was naturally turned to the " so- 

 called animal," our ignorance of the habits of which is so well brought 

 out in the " colours of cowries," rather than to the points in connection 

 with the shells which have been known for Lrenerations. 



