On a new Species of Cjinonoinas. 5C5 



tmnk ; with smooth hyaline spicales bearing peculiar 

 di^tiform t«nninal processes and showing very characteristic 

 annalationS| especially near the ends. 



Locality. Cheval Faar, S.B. of Ceylon, 6 fathomg. 



EXPLANATION OF PLATE XVH. 



Fig. 1, Fvudioilarui H*!rdmam., Ts-i^ole oolonj, natural Hze, 



Ftg. 2. Portion etalarg-txi, stowinw the diiffeireat Btatres of retraction of the 



Fig. Z. Traosreree section of tie stock, shoirin^- three central eanals- 

 Fig. 4- SjHcaJes of the cortical lajer or caticle. 

 Fig. 5, Spicoles of the body-pai^Hiclj jma. 

 Fig. it. Spicules of tiie troak. 



LXXVIII— JSoTMra/ History Notes from the R.LM.S. Ship 

 'Investigator/ Capt. T. H. Heming, R.\., commanding. — 

 Series III., No. 9. On a new Species of the Dori/jpoid 

 Genus Cymonomus from the Andaman Sea, considered wiih 

 reference to the Distribution of tfie Dorippidae ; with some 

 Remarks on the allied Genus Cymonomopi?. By A. Alcock, 

 M.B., LL.D., F.R.S., Superintendent of the Indian 

 Museum and Professor of Zoology in the Medical College 

 of Bengal. 



[Pla.te X^IIL] 



C-OXTUKTK, 



1. Cgmonnmius ami Ihe Ihrippid.ce. 



2. Cynvauimjuiii dbaraetesized, stnd C. anicmanicus distingTiiehed and 



diffeP^DitiatecL 



3. Geogm^deal IHstribiilian of Qfmonomus and other Doiippoid 



4. Bemazks oa tbe Genus Cymon&nMp*. 



o. List of the iMtrippid^. 



1. Cmosours and the Domifptdje. 



The small blind deep-sea crabs of the genus Cymonomus 

 have, in the 'Quarterly Journal of Microscopical Science' for 

 December 1903, formed the subject of a paper, by Professor 

 Bay Lankester, of much interest both biological and taxo- 

 Bomic ; so that the discovery of a representative of the jjenus 

 in the Andaman Sea may, perhaps, be thought worthy of 

 independent notice, especially as it invites zoogeographical 

 inqniries that seem to deserve consideration. 



Cymonomws belong to the Oxystome family Dorippidae — 

 a primitive family, in the typical members of which, as in 



