102 DR. C. L. BOULEXGER ON 



run longitudinally down the body, each about halfway between 

 the middle line and the margin. Although expressed somewhat 

 differently, it will be seen that this colour-pattern is practically 

 identical with that described by v. Grafl" (8) in M. ruhrofasciatum, 

 a Myzostomid obtained from an unidentified Crinoid in the Red 

 8ea at Tur, near Sinai. I think there can be no doubt that 

 Mr. Crossland's two specimens must be referred to the same 

 species. 



V. Graff's description was based on a single individual, which 

 was more brightly coloured than those I am describing, moreover, 

 at first sight it seems to differ considerably in shape from those 

 specimens. This difference is, in my opinion, due entirely to the 

 mode of contraction, the body in v. Gi'aft''s specimen having the 

 sides bent ventrally so as to give it the form of a boat, the median 

 elevation I'epresenting the keel. 



Owing to the state of contraction of his only specimen, v. Graff 

 v,-fiH not able to describe the ventral surface at any length. In 

 the individuals collected by Mr. Crossland the ventral surface is 

 yellowish in colour, and the central musculai* mass prominent. 

 The five pairs of parapodia are well developed and, as in 

 M. costatum, without division into proximal and distal regions ; 

 they arise approximately halfway between the centre of the body 

 and the margin. 



There are foiu^ pairs of suckers of relatively large size with 

 radially folded walls. They are in the normal position between 

 tlie parapodia, and are situated close to the periphery. 



Both mouth and cloaca are subterminal. 



The male papillae are not conspicuous ; they have the form of 

 short conical processes in the usual position lateral to the third 

 j)air of parapodial bases. 



I did not feel justified in cutting sections as I had only two 

 specimens of this species at my disposal, and neither seemed likely 

 to yield good results. One individual was cleared in cedaiwood 

 oil, but owing to the thickness of the body revealed practically 

 nothing of the intei'nal organisation. 



Myzostoma crosslandi, sp. n. (PI. VI. figs. 2, 3 ; PI. VII., 

 & PI. VIII. fig. 1.) 



From various localities in the Red Sea Mr. Crossland obtained 

 four specimens of a large elongated Myzostomid (PI. VI. figs. 2, 3) 

 which is evidently closely related to M. vianseni v. Giaff", but suffi- 

 ciently distinct, in my opinion, to justify the creation of a new 

 species to receive it. This form, which I name M. crosslandi, 

 is in certain respects intermediate between M. nanseni and 

 M. folium V. Graff. 



Of the four individuals one was found at Ul Shubukon Ayitedon 

 savigni/i, another in Suez Bay a,t a depth of 10 fathoms on 

 Antedon serripinna, whilst the other two wei-e obtained from a 

 Comatulid which I have been unable to trace. 



As mentioned above, this Myzostomid is of comparatively large 



