200 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



and affords many new records of species not hitherto found in the 

 Philippine region, thus increasing the known range of such forms. 



One interesting feature of the collection is the relative scarcity 

 of gymnoblastic forms, there being but three species belonging to this 

 group, and one of these, Branchiocerianthus imperator, was dredged 

 in Japanese waters and does not belong properly in this collection. 

 On the other hand, 26 species, almost one-half of the total, belong to 

 the one family, Plumularidae, and this family was divided almost 

 equally between the eleutheroplean and statoplean forms, there being 

 12 of the former and 14 of the latter. 



It is interesting to compare the general f acies of this collection with 

 that reported on by Doctor Hargitt, 4 which contained about 50 

 species, 13 of which were gymnoblastic and the remainder calyptero- 

 blastic forms and among the latter were but 7 species belonging to the 

 family Plumularidae. This difference is doubtless due in part to the 

 greater average depth of the stations worked by the Albatross, the 

 Plumularidae usually thriving best in rather deep water. But the 

 difference in the number of gymnoblastic forms represented in the 

 two collections is hard to explain, although it may be due to a good 

 deal of shore or tide-pool collecting in the case of the material re- 

 ported on by Doctor Hargitt. 



Family TUBULARIDAE 



BRANCHIOCERIANTHUS IMPERATOR (Allman) 



Monacaulus imperator Allman, Challenger Reports, the Hydroida, pt. 2, 



1888, p. 5. 



The specimen secured by the Albatross is much smaller than those 

 heretofore reported, but I find no good specific differences. The 

 hydrocaulus is but 26 cm. long to the base of the hydranth. Height 

 of hydranth 2 cm. and diameter 8 mm. One of the outstretched 

 tentacles measures 7y 2 cm. in length. Compared with the enormous 

 dimensions of the type specimen as recorded by Allman — hydranth 

 iy 2 inches, tentacles 4 inches long, with a stem 7 feet 4 inches high — 

 the present specimen is relatively small, although it bears sexually 

 mature gonophores. 



The excellent descriptions and figures given by Stechow 5 agree 

 very well with the specimen at hand except in size, his figure indi- 

 cating a length of hydrocaulus of 85 cm. 



In structure and characters of the proximal end of the hydrocaulus 

 the Albatross specimen agrees very closely with that described by 

 Stechow. The hydranth has been badly mutilated presumably by 

 the dredge or trawl and the bilateral symmetry which Stechow 



* Hydroids of the Philippine Islands, 1924. 



5 Beitrage zur Kenntnis von BranohioceriantJius imperator, Miinchen, 1908. 



