Miscellaneous. 181 



related to L. Lehouri, described by Mr. Percy Sladen before this 

 Society in 1879 ; but it also has affinities with L. cincinnatiensis 

 and L. squaiiiosus. From all these, however, the present specimen 

 differs in havinfi: the pyramid in the middle of the interradial space, 

 in possessing shorter arms, and in being much smaller. This fossil 

 is to be named Lcjmlodisvus Milleri, after Mr. Hugh ililler, under 

 whose direct ion these fossils were collected by Mr. J. llliudca. 



U. " Arcliceopneusies ahruptits, a new Genus and Species of 

 Echinoid from the Oceanic Series in Barbados.'' By J. W. 

 Gregory, Esq., B.Sc, F.G.S. 



This genus belongs to a group of Echinoidea which has given 

 some trouble to systematists, owing to the union of the characters 

 of the orders Cassiduloidea and Spatangoidca ; the other genera 

 belonging to the group are Asterostoma, Pseudasterostoma, and 

 J'alaojmcvstes. The evidence of the new Echinoid throws light 

 upon the aflinitics of these genera. The main points suggested by 

 a study of the new species are : — (1) the abandonment of the name 

 Pseudasterostoma as a synonym of Palaopneustes ; and (2) the 

 ijiclusion of the true Asttrostouia , Pahpojjneiistes, and Archa'ojjneustes 

 in the Adete S})atangoidca, whereby the Plesiospatangidte are left as 

 a more homogeneous family, though bereft of the chief interest 

 assigned to it. 



A tabular summary of the nomenclature of the group is given. 



The b€st-known fossil species of Asterostoma and Palnopnetistes 

 occur in Cuba, in deposits referred to the Cretaceous owing to the 

 resemblance of these Echinoids to the common Chalk Echinocorj/s 

 scutatus. The new genus includes a species from the same deposit, 

 which is probably of the same age as the Bissex Hill rock from 

 which the new species was obtained ; this is at the top of the 

 Oceanic Series, and belongs to the close of the great subsidence. 



MISCELLANEOUS. 



Xote on Abnortn^ilitles in the Orai/Jish (Astacus fluviatilis). 

 By W. N. Parkek, Ph.D. 



While a number of crayfishes were being dissected bj' my students 

 last month I noticed that three of the specimens presented certain 

 abnormalities which, although peihaps not so interesting as the case 

 recently described in this Journal by Benham*, are probably worthy 

 of record. 



Specimen I. — On the left side, in addition to the normal pleuro- 

 branch of segment 13, a small but well-developed gill was present 

 on the wall of segment 12 in place of the usual rudimentary style. 

 This gill was about three quarters as long as the pleurobranch 

 normally present. 



Specimen II. — The last arthrobranch of the left side, /. e. the 



* " Note on a Couple of Abnormalities," ' Annals,' ser. 6, vol. vii. uo. 39, 

 March 1801, u. 256. 



