Hyatt.] 286 [April 4, 



spout-like as in the tubercles of Rutoceras. The remarkable 

 species with form and tubercles like Temnocheilus, but a ridged 

 abdomen, the Koph. (Naut.) Coxanum, M. et. W. Geol. 111. Vol. 5, 

 pi. 23, is probably in this genus. 



Strophiceras, 1 nobis, includes a Devonian gyroceran form Str. 

 (Gyr.) binodosum, sp. Sand. Verst. Nass. pi. 12, which has a com- 

 pressed whorl with gibbous tuberculated abdomen, and flattened 

 sides. There are several rows of tubercles upon the abdomen as 

 in Kophinoceras, but also a central row of tubercles. Sutures 

 with ventral, lateral, and dorsal lobes, but no annular lobes. Form 

 probably close coiled. Siphon ventral. The form is peculiar, 

 the young unknown, and we refer the species to this series with 

 great doubt. 



Solenoceras, 2 nobis, includes species of the Carboniferous, 

 Dyas, and Trias having remarkably heavy looking quadrate 

 whorls with furrowed abdomens. Sutures, with broad ventral, 

 lateral, and dorsal lobes, and in adults a small annular lobe may 

 appear in some species. Siphons central and nummuloidal. Liv- 

 ing chamber is one-fourth to one-half a volution in length, aper- 

 tures with very deep ventral sinus. The shells are smooth except 

 in the young and some adults of Solen. (Naut.) nodosum, which 

 has a single outer row of large nodes along the sides. Type, 

 Solen. (Naut.) canaliculatum, sp. Owen, Geol. Ken. Vol. 3, pi. 

 10. Mus. Comp. Zool. This genus * includes a series of Dyassic 

 species described by Waagen Pal. Ind., ser. 13, no. 1. Solen. 

 (Naut.) transitoriuum sp. Waag. ibid, pi. 6, fig. 4. They have 

 quadragonal whorls, are costated, and have depressed or furrowed 

 abdomens. Siphons below the centre slightly or central ; Sutures 

 with ventral, lateral, and dorsal lobes. Annular lobes? 



Phloioceras, 3 nobis, includes the so-called Trematodisci of 

 the Trias described by Mojsisovics in his "Mediterr. Trias 

 Provinz." The shells are ridged longitudinally, and the ridges 

 in the type roughened by transverse striae. Mojsisovics considers 

 them as allies of Naut. cariniferus, and he may be right, but we 

 have placed them in this series on account of the resemblance of 

 gemmatus to Kophinoceras. The sutures have simple, lateral, 



1 2Tpocj>€iov, a twisted rope. 



2 SwXrjv, a groove. 

 8 4»\otos, bark. 



