20 



years later, still further enriched tiie subject hy an account of 

 Annelids from the East African region — chiefly south of 

 Zanzibar. Lastly, an important collection has recently been 

 made at Zanzibar, by a young and able observer, Mr. Cyril 

 Crossland, and a report on certain groups has been published.* 

 When the examination of these is completed, much information 

 on the Annelids in general as well as of the Geographical dis- 

 tribution of the group will be available. 



Dr. Gilchrist's collection was made between tide-marks, and 

 probably indicates the most conspicuous forms of the region. 

 In glancing at the series, it is found that the Polynoid^e, 

 Phyllodocidfi?, Syllidae, Nereidae, and Sepulidie have but few 

 representatives, and the Hesionidse are absent, yet all of them 

 usually are found in numbers under stones, between tide-marks, 

 in a prolonged search. Their number will probably receive 

 considerable additions in future. The forms frequenting sand, 

 or sandy mud, are for the most part absent, either because 

 digging was not resorted to, or because the region was purely 

 rocky. The Annelids generally found in the media mentioned 

 are the Nephthydidaj, Glyceridie, Opheliid?e, Scalibregmidai, 

 Telethusae, Spionidte (including Mageloiia),3.nd Ammocharidae, 

 whilst in deep water the Ampharetida; are frequent. Doubt- 

 less, the groups mentioned will be represented when the trawl 

 and dredge are used. The trawl-net is especially productive — 

 not only in regard to the debris of old bivalve and univalve 

 shells in which Annelids lurk, or have their tubes coiled within 

 them, but from the frequency with which soft Annelids, both 

 errant and tubicolar (now devoid of a tube) cling to the meshes. 

 By the flashes of phosphorescence, even small forms like the 

 Syllida? and Polycirrus may be secured at night, whilst the 

 bright colours of others, such as the Nemeteans and Hesionidse 

 readily distinguish them by day. Many Annelids are minute, 

 and require careful inspection of the apparatus for their detec- 

 tion. Special inquiry should also be directed to the forms 

 which bore in calcareous rocks, in or under crusts of Melobcsia, 

 in shells, or softer media, which become pelagic, like Palolo, at 

 the reproductive period, or which are useful as bait ; indeed, 

 there are few which are not available for the latter purpose. 

 The purely pelagic types such as Alciopa, Halodora, Phalacro- 

 phorus, Pelagobia, Haliplanes, and Lopadorhynchits, and the 

 temporarily pelagic, such as Aiitolytus, may also occur in tow- 

 nets along with Tomoptetis, and the larval and post-larval stages 

 of the sedentary types. 



Much may likewise be accomplished by splitting the rocks 

 between tide-marks with hammer and chisel, or using a lever 

 to overturn large stones and separate shelving rocks — in the 



*Proceed. Zool. Soc, 1903, Part I., p. 169, Pis. xvi & xvii., and Part II., Aug., 1903. 



