ECHINOIDEA. II. 2,7 



porus. The apical system differs from tliat of grnndiporits in the ocular pores being much smaller tlian 

 the genital pores as is the case in pusillus. The madreporic plate is generally larger thau in grandi- 

 porns. otherwise it is elevated as in that species and the genital pores are likewise covered with long 

 genital papillæ. Also in tliis species I have seen oue specimen with 5 distinct genital pores. The pe- 

 tals are verv slightlv developed, even scarcely so much as in graiidiporus, as seen by the foUowing 

 table. The genital pores I find developed in the specimen of 4'"'", while in that of 4-2""" they have 

 not \'et appeared and in the specimen of 4-8'""' (the one figured) only the anterior pair is developed. 



As regards the arrangement of the actinal pores, the tuberculation, the structure of pedicellariæ 

 and spines as well as the internal structure of the test I do not find any reliable differences from grandi- 

 porus. (PI. XII. Figs. 2 and 7 represent au ophicephalous and a triphyllous pedicellaria of this species.) 



The colour of the living animal is, according to the sketch made on board the Valdivia , 

 green; there are ten darker radiating bands, answering to the bands of tube-feet, the intermediate 

 spaces having a slight yellowish tint; around the peristonie there is a darker pentagon, radiating a 

 little into the ambulacra. 



Number of pairs of pores in Echiiio- 



To this species belongs the specimen referred to Eciihiocya- oiamus macrostomus. 



mus pitsillus from the German Deep-Sea Expedition, St. 37, 1694 m. 

 (off Cape Verde. Doderleiu op. cit. p. 234), aud the two specimens 

 from the Travailleur 2100 m., which I received from the Paris- 

 Museum. Further, amoug the specimens sent me by Professor 

 Koehler two specimens from 37° 54' Lat. N. 27° 3' Long. W. 2178 m. 

 (off the Azores), three specimens (the Azores, 1360 m.), one living speci- 

 men aud some dead tests from 32° Lat. N. 16° Long.W. 2286 ni., and one 

 specimen from 39' Lat. N. 32^ Long.W. 1600 m. belong to this species. — 

 The species is then evideuth' a more abyssal species thau graudiporus. 



I have been in considerable doubt as to whether this form ought to be established as a sepa- 

 rate species or not. It is Ijevond doubt that it is very closelv related to Ech. graudiporus^ from which 

 species it is distinguished onl\- by the .small size of the ocular pores aud the large size of the peri- 

 stonie, other small differences beiug too iuconstaut to be relied upon as specific characters. The 

 two features poiuted out are, however, so conspicuons and so far as niy e.xperience goes constant, 

 that it seenis quite necessary to keep this form separate, as the bathymetrical distribution seems also 

 to indicate its .specific difference from grandiporus. Otherwise it is evideuth' of 110 great importance 

 whether it is regarded as a variety only of the latter species or as a separate species; the main thing 

 is that it should not be mereh- coufouuded with the typical grandiporus — not to mention pusillus 

 with which it was hitherto confouuded, but to which it is not so nearh' related. 



Perhaps vet another species of Ecliiuocyninus will prove to occur in the Atlantic. Amoug the 

 specimens from the Josephina > aud amoug those from the Azores sent me by Professor Koehler 

 there are a few small specimens, which look ratlier differeut from the other species. They agree with 

 pusillus in the shape of the test, the small size of the ocular pores and in the petals. But the pri- 

 mary tubercles are larger thau is generally the case in pusillus, aud the scrobicular area is more 

 deepened. Further, it ma>' be uoticed that the tnbercle is placed excentricalK' at the anterior side of 



