8 EEPOET OF COMMISSIONER OF FISH AND FISHERIES. 



common in Europe, is very rare with us, having been found in but one 

 locality in the United States and one in Nova Scotia. Fucus canalicu- 

 lattis, Himanthalia lorea, and the common European Cystoseircc are 

 quite wanting. The nearly ubiquitous Codium tomentosum is a species 

 which has not yet been found on our northern coast. On the other 

 hand some species, as Spyridia filamentosa and Chordaria divariaita. 

 more abundant in New England than in Europe, and the same is prob- 

 ably true of EutJwra cristata and Ptilota serrata, if we except perhaps 

 the arctic zone. 



It is evident that a great deal remains to be done before we can say that 

 we have as accurate a knowledge of our marine flora as we have of that of 

 most European countries. Hereafter any advance in the knowledge of our 

 marine algse must be made by a careful microscopic study on the shore. 

 Probably all the large and striking species are now known, or if any re- 

 main to be discovered their discovery will be by mere chance, and not by 

 any systematic search. What is especially needed is information about our 

 winter and spring forms, and this can be best obtained by persons who 

 either live on the shore or spend several months there, so as to be able to 

 take advantage of the comparatively few days for collecting, which oc- 

 cur in our severe winters. The habits and structure of our Laminarlce 

 need careful examination, microscopic as well as in the gross. The 

 whole order of the Phceosporece, in fact, which abound in spring, should 

 be studied, especially the genus Ectocarpus and its allies. Our Cladophorce 

 are in great confusion, and in the present paper I have been able to 

 contribute but little towards their proper arrangement. Several years 

 of study are necessary for the purpose, and, in fact, the task cannot well 

 be accomplished until the European species are better known. Our 

 Ulvece are not in much better condition. The Ulvce proper, thanks to 

 the elaborate account of the genus given in Le Jolis's Liste des Algues 

 Marines de Cherbourg, can be tolerably well made out j but the deter- 

 mination of some of the species of Monostroma is merely approximate. 

 The Cryptophycece, which inhabit the shores and brackish localities, are 

 very numerous, and a large number of forms probably remain to be dis- 

 covered. A study of the last-named order is, moreover, not without a 

 practical bearing, as is shown in another part of the report, by the fact 

 that the cause of the so-called red fish is due to the growth of an alga of 

 this order. It is probable that we have with us nearly all the European 

 species of this order, and an excellent guide for our students, is the ad- 

 mirable paper by Warming on the Bacteria of the Danish Coast.* 



Another group requiring study is the Squamariece, a small order con- 

 sisting of species, which form crusts on stones and shells, often in deep 

 water. As a rule comparatively little in the way of sea- weeds is found 

 by dredging ; but an examination of shelly and gravelly bottoms for 

 Squamarice is to be desired. Dredging is most successful between 10 



* Oin nogle ved Danmarks Kyster levende Bakterier, in Videns. Med. Natu r. Foren., 

 Copenhagen, 1875. 



