ABT. 14 FOSSIL AND EECEFT BRYOZOA CANU AND BASSLER 



117 



r~\. 



(X 85); their diameter is in the neighborhood of six-thousandths of 

 a milKmeter (0.006 mm.) 



Affinities. — This species differs from Smittina trispinosa Johnston, 

 1838, in its larger dimensions, in the presence of two oral spines, and 

 in the greater diameter (0.35 mm.) of its ovicell. It differs from 

 Smittina tripora Canu and Bassler of the Philippines in the absence 

 of two rather constant peristomial avicularia and in the presence of 

 a large frontal avicularium. 



The S. trispinosa group is very disconcerting in its zooecial irregu- 

 larity and its false tremocyst. We were inclined to form a special 

 genus for it, but we do not yet see any physiologic function M^hich 

 could differentiate it from other Smittina. However, it is a homo- 

 geneous group to the trained eye of the specialist. Smittia coUaris, 

 variety Waters, 1883, a fossil of the Miocene at Muddy Creek, Aus- 

 tralia, is another species of 

 the same group in which a 

 small tongue sometimes re- 

 places the distal spines. 



Biology. — Our specimens 

 were living and ovicelled 

 January 19, 1885. The great 

 irregularity of the avicularia 

 is difficult to understand. 

 It is difficult to admit that 

 chance and fantasy are the 

 only reasons for their pres- 

 ence ; they are not ornaments 

 but they are indeed special 

 organs always in activity. 

 Their appearance seems to 

 be in connection with an 

 immediate necessity, but es- 

 sentially variable and chang- 

 ing, that each cell contributes 

 to the profit of the colony. 

 There is then an undoubted instinct, almost a kind of reasoning, 

 permitting an adaption more easily to its environment. 



Occurrence.— Albatross Station D. 2339; 23° 10' 40" N.; 82° 20' 

 15" W.; 191 fms. 

 Albatross Station D. 2639, Straits of Florida; 25° 04' 



50" N.; 80° 15' 10" W.; 56 fms.; coral sand. 

 Florida, 21 and 71 meters (Smitt); Tortugas, low 

 water, 20 meters (Osburn). 



Cotypes.—C&t. No. 7560, U.S.N.M. 



Fig. 22.— Family Smittinidae. A. Smittina labellum, 

 NEW SPECIES. Operculum, X 85 doubtfully keferred 



HERE. B. UMBONULA UNDULATA, NEW SPECIES. OPER- 

 CULUM, X 85. C, D. Palmicellaria aviculifera, new 

 SPECIES. C. Operculum, X 85. D. Mandible, X 250. 

 E, F. Rhamphostomella magnirostris, new species, 

 H. Mandible, X 85. F. Large mandible, X 85. O. 

 n. Smittina labellum, new species. Two opercula, 

 X 85 



