REVIEWS. 17 



Two Bostrychia (B. montagnei and B. Jilicula, MS.), and a Catenella, 

 were found on the stems of mangroves, near high-water mark. 



Such is Dr. Harvey's outline of the distribution of the leading types 

 found in each of the four regions into which he proposes to divide the lo- 

 calities, the result of whose examination is contained in the present Nereis. 

 We have presented it to our readers, as we feel assured that it will be read 

 with interest by all who wish to form some idea of the characteristic 

 vegetation of the North American shores. The parts which we have 

 extracted are prefaced by a few brief observations on the general causes 

 that appear to affect the geographical distribution of the Algae. These will 

 be read with confidence and interest by all, as affording, in an able summary, 

 the results of observations made by some of the best algologists, grouped 

 together by one who is himself more capable of appreciating the importance 

 of such generalizations than, perhaps, any of his fellow-labourers in thi3 

 line of research. We would gladly transfer them to our pages ; but we 

 feel that, however unwilling, want of space compels us to draw our 

 present notice to an end. When comparing the genera recorded in these 

 volumes with the same genera as found described by our author in 

 his Phycologia Britannica, we are often surprised with meeting old 

 friends under new names, and sometimes names that we were familiarized 

 with, from the pages of Phycologia, unceremoniously transferred to new 

 faces. We fear that in this respect some of the Algae could make out a 

 very clear case against the learned Professor and some of his brethren — as 

 for example, the Ralfsia deusta (Berk and Phyc. Brit.), which, after hav- 

 ing passed through six different genera, hoped to have found its true name 

 in the pages of the Phycologia Britannica; and yet, on the ap- 

 pearance of the NereVs B or eali- Americana, finds that his fair name 

 has been pilfered by an American stranger, patronized by J. Aghard, and, 

 after all his previous sufferings, the poor Alga is again left in quest of a 

 name. We are sure the learned professor " did it all for the best," and, 

 therefore, will not say a word more than to warn our readers, that the 

 American plant is not the British plant described under the same name. 



In the introduction prefixed to the sub-class Rhodospermeae, Dr. Harvey, 

 after briefly stating the general characteristics of the Algae included in it, 

 proceeds to an examination of the double system of fructification, which 

 forms their most remarkable and distinctive character ; " two descriptions 

 of spore-producing organs being found on almost all these plants, and 

 always being developed on different individuals of each species. Thus, then, 

 Algae are strictly dioecious, though in a different manner from other dioecious 

 plants ; for here it is not stamens and pistils (or their analogues) which are 

 VOL. i. c 



