2 Dr. T. Davidson on a Jwing Spinose Rhynclionella. 



slightly sinuated and forming in front a more or less elevated 

 curve. Surface of valves marked with numerous delicate radi- 

 ating ribs, with interspaces between them of almost equal 

 width, and increasing in number at variable distances from 

 the beak by the interpolation of shorter riblets. Ribs num- 

 bering in full-grown specimens sixty, close to the margin. 

 Valves closely crossed by numerous equidistant concentric 

 raised or foliated lines of growth, giving rise at the margin 

 on each riblet to short, sloping or erect, hollow spinules. 

 Shell-structure fibrous, colour light yellowish grey. In the 

 interior of the dorsal valve are two short curved lamellae for 

 the support of the labial appendages. Length 12, breadth 13, 

 depth 7 lines *. 



In the young state the shell is much flatter, without a 

 mesial fold, the ribs are fewer in number, and the spines have 

 not yet become developed. Number of ribs about thirty, half 

 of Avhich originate from the interpolation of shorter ones 

 between the others ; some are also due to bifurcations. 



Habitat. Several specimens of this new and interesting 

 species were dredged by Dr. L. Doderlein in the living state in 

 about 160 fathoms in Sagami Bay, Japan. R. Ddderhini is 

 often found attached to corals. 

 It was associated with Hexac- 

 tinellidie, the crab Lithodes 

 hystriXj Laqueus riihellus, Ter. 

 Blanfbrdii, and T. capnt- 

 serpentis. I am informed by 

 Dr. Doderlein that it was 

 dredged close by "station 232" 

 of the ' Challenger' Expedition, 

 but a little nearer the coast, 

 in from 100 to 250 fathoms. The 

 sea-bottom was covered with 

 mud, stones, and volcanic debris, 

 and was rich in animal life f. 



Observations. — In this very 

 remarkable species, by far the 

 most noteworthy of all the living 

 members of the Rhynchonellidee, 

 the spines project from each rib. 

 They are arranged in regular 

 rows, and not irregularly scat- 

 tered over the surface of the 

 shell, as in Eh. spinosa, a some- 



* [Dr. Davidson's description verbatim. — A. C] 



t No less than thirty-two species of Bracliiopoda have now been 

 obtained from Japanese and Chinese waters. 



A. Adult lih. Boderleini, 

 Dav. 



B. Portion of external sur- 

 face enlarged, to show ribs, 

 interspaces, concentric lines, 

 and spines. 



