Homotrypa obliqua

• Shape variable, from cylindrical to fan-like. Apertures enlarged in maculae

Bassler (1903)

• This abundant Lorraine species in its internal characters is very much like H curvata. The absence of diaphragms and the slightly crinkled walls in the axial region distinguish it from H. curvata. Externally, however, the two species are readily separated by their different methods of growth, the ramose zoarium of H. obliqua with its cylindrical or slightly compressed, more or less tuberculated, branches being quite characteristic. In the fairmount beds of the Cincinnati area a form of the species with strongly tuberculated, cylindrical branches seldom over 5 or 6 mm. in diameter, occurs very abundantly. The succeeding Bellevue beds also hold the species in abundance, but here the zoarium is more robust and the branches are often subcylindrical and nearly smooth. Specimens 6 cm. or more in length without dividing and 15 mm. in diameter are often found. The prevailing form of zoarium in the Corryvile beds is a rather broad, somewhat compressed, tuberculated branch, and specimens of this kind probably led Nicholson to identify H. dawsoni at Cincinnati. The internal structure of these various forms of the species is essentially the same. About 10 zooecia in 3 mm.