OP ARTS AND SCIENCES. 191 



material. I shall, of course, not hesitate, in my final report on the 

 Challenger Echini, to avail myself of this additional material. It is 

 quite important, both from a systematic point of view and for deter- 

 mining more accurately the bathymetrical range of the greater num- 

 ber of the Challenger Echini, showing, as it does, that many species 

 thus far considered as deep-sea species approach very nearly the 

 hundred-fathom line. 



Among the Cidarid^e, in addition to the new species of genera 

 well known before, the most interesting form is a fine species of 

 Porocidaris,n.. sp. (P. elegans,A. Ag.). Large and valuable material 

 was also collected for the study of Goniocidaris canaliculata, A. Ag., 

 including its earliest stages, and many varieties, as well as a most ex- 

 tensive series of Goniocidaris tubaria, showing a range in the varia- 

 tion of the spines unknown in any other species of the genus. 



A new species of Salenia (S. hastigera, A. Ag.), the third now 

 known, was also discovered. Of this many specimens were collected. 



Among the Arbaciad^e I note a species of Porocidaris (P. prio- 

 nigera, A. Ag.), and a large series of Coelopleurns Maillardi. This 

 has enabled me to make a careful study of this interesting genus. 



In the family of DiADEMATiDiE, a new genus allied to Astropyga, 

 Micropyga (M. tuberculatum, A. Ag.), and two species of a genus 

 closely allied to Trichodiadema, Aspidodiadema (A. tonsum, A. Ag., 

 and A. microtubercidatum, A. Ag.), have been collected. 



Among the Echinothuri^e a number of new species were 

 dredged, both of Asthenosoma and of Phormosoma, in addition to the 

 species already described by Sir "Wyville Thomson in the " Echini of 

 the Porcupine," the " Depths of the Sea," and the " Voyage of the 

 Challenger." They are A. pellucida, A. Ag., A. Grubei, A. Ag., 

 A. tessellata, A. Ag., A. coriacea, A. Ag., P. lucidenta, A. Ag., and 

 P. tenuis, A. Ag. Several small specimens of these genera were also 

 collected, but it will be impossible to do more than refer them tem- 

 porarily to existing species, as the material is hardly sufficient for 

 exact determination. I hope, however, by making use of the many 

 young Echinothuriae collected by the Blake for comparison, to deter- 

 mine them more satisfactorily. 



Among the Echinometrad^e nothing of importance was collected. 



Among the Temnopleurid^e excellent series of the species of Sal- 

 macis and of Temnopleurus were obtained ; a new species of Trigono- 

 cidaris (T. monolini, A. Ag.), a Cottaldia (C. Forbesiana, A. Ag.), 

 hitherto only known from the Chalk, and an exquisite genus, Prio- 

 nechinus (P. sagittiger, A. Ag.), allied to Salmacis and Podocidaris. 



