662 SUMMARY OF CUBEENT RESEARCHES RELATING TO 



description of the new forms, already described in the Bulletins of 

 the Museum of Comj)arative Zoology at Cambridge, U.S.A., the author 

 has included the names and distribution of, with references to some 

 of the literature on, previously described species. Keys of the specific 

 characters are given with most of the genera, and geographical and 

 bathymetrical lists complete the work. Anatomical observations have 

 been made on some species, and are incorporated as occasion offers. 

 There are, however, no general remarks on the arrangement of the 

 genera, and the introduction is chiefly remarkable for its attack on 

 two principles dear to most modern zoologists ; one is the application 

 of the doctrine of descent, and the other the necessity of applying 

 definite technical terms to definite characters and conceptions. Mr. 

 Lyman, in genial but strongly expressed paragraphs, expresses his 

 views on these questions. 



New Ophiuroids.* — T. Lyman remarks that the West Indies are 

 the hotbed of Echinodermata ; more than a quarter of the known 

 Ophiuroids are from that region, and nearly all genera are found 

 within it. As in other groups of animals, some genera are very rich 

 in sjiecies, Ophiocflypha, Amphiura, Oyhiacantlia, and OpMothrix con- 

 taining two-thirds as many species as do all the remaining 68 genera 

 in the family. A peculiar structure does not, as Ophiomyxa bears 

 witness, necessarily entail abundance of sjiecies. The author gives a 

 technical account of a number of new species, one of which, Opkiocreas 

 spinulosus, lives, like some other forms, in great colonies. The 

 tangles often came so clogged with hundreds of specimens that it 

 was necessary to cut them off and thi-ow the mass into alcohol. 



New Crinoid from the Southern Sea.t — P. H. Carpenter de- 

 scribes a small Comatida which was dredged by the ' Challenger ' at the 

 depth of 1800 fathoms in the Southern Sea. Although it is unusually 

 small, the diameter of the calyx being only 2 mm., the characters pre- 

 sented by this form are such as to render it by far the most remark- 

 able among all the types of recent Crinoids, whether stalked or free. 

 The name proposed for it is Tliaiimatocrinus renovatus. It is distin- 

 guished by four striking peculiarities : — 



1. The presence of a closed ring of basals upon the exterior of the 

 calyx. 



2. The persistence of the oral plates of the larva, as in Hyocrinus 

 and Bhizocrinus. 



3. The separation of the primary radials by interradials which rest 

 on the basals. 



4. The presence of an arm-like appendage on the interradial plate 

 of the anal side. 



Taking these in order — 



1. No adult Comatula, except the recent Atelecrinus and some little- 

 known fossils, has a closed ring of basals, and even in Atelecrinus they 

 are quite small and insignificant. 



2. In all recent Comatulce, in the Pentacrinidce, and in Bathy- 



* Bull. Mus. Comp. Zool. Camb., x. (1883) pp. 227-87 (8 pis.), 

 t Proc. Roy. Soc, xxxv. (1883) pp. 138-40. 



