DEPARTMENT OF MARINE BIOLOGY. 12/ 



In addition to these there are 4 distinct species belonging to the group 

 which I have been recording under the generic name Monostomum, but 

 which will have to be assigned to a different genus, or, more probably, to 

 different genera. Furthermore, there are at least 10 distinct species which 

 differ so much from any genera included in Pratt's Synopsis that it can not 

 be said of them that they are even near any of those genera. In some cases 

 it is true that the material is in poor condition, so that the anatomy is incom- 

 pletely shown. At the same time, the greater part of the material is suffi- 

 ciently well preserved to show the anatomy satisfactorily. 



One of the new forms is an endoparasite of the black angel-fish (Poma- 

 canthus arcnatus), which appears to be a new genus of the Tristomidge, in 

 which the anterior suckers are rudimentary. 



From the loggerhead turtle the following genera of trematodes were ob- 

 tained: Calcyodes, Cyniatocarpus, Orchidasmus, and one undetermined form 

 which is probably a new genus. 



Summary of Investigations at Tortiigas, igo8, by J. F. McClendon, 

 University of Missouri. 



STUDIES OF SEA-ANEMONES. 



During the last half of June and first half of July a number of reef animals 

 were studied, and a reef anemone and 2 crustaceans living in the loggerhead 

 sponge found to be especially interesting. 



The sea-anemone Cradactis sp. (?) is apparently new and was given to Dr. 

 Hargitt for systematic description. This anemone differs in habits from all 

 other anemones I know of, in being able to crawl on its tentacles. Therefore 

 its general behavior was studied so that comparison might be made with the 

 behavior of other anemones. The outward form is similar to the type species 

 of Cradactis in the presence of branched tentacle-like structures or "fronds" 

 outside the ordinary tentacles. These fronds are so shaped and colored as to 

 give the appearance of sea-weed. The animal lives in cavities in coral heads 

 having openings to the exterior through which the fronds are protruded dur- 

 ing the day (they being contracted at night). When crab-meat is held near 

 the cavity containing the Cradactis there is no response until the meat touches 

 the fronds, when the tentacles are extruded, grasp the meat, and carry it to 

 the mouth. Sections show the fronds to be supplied with nematocysts and 

 mucus glands, and they may catch food, but they do not carry it to the mouth. 

 To observe the further feeding reactions, the anemones were taken out of the 

 coral and placed in dishes of sea water. When a bit of crab-meat is placed 

 on the end of a tentacle it adheres, and the tentacle and one or more adjacent 

 ones are bent over, and the food placed on the mouth. Immediately many or 

 all of the tentacles are pressed on the food, and the mouth widens and swal- 

 lows it. 



Cradactis sometimes swallows filter paper placed on the middle of the 

 tentacles or on the disk, but not when placed on the tips of the tentacles. 

 Possibly in the last case less area is stimulated. The filter paper is disgorged 

 within ten minutes. India-ink shows ciliary currents running toward the 

 tips of the tentacles and fronds, and on the disk toward the mouth. The 

 animal is disturbed by light falling on its base, and may move a short dis- 



9 — YB 



