49 



This definition is a satisfactory one for our present purpose, and will be adopted. 



The type species of this genus is Mopsella textiformis (Lamarck). Other described 

 species are Mopsella amboynesis Kiikth., M. clavigera Ridley, M. dichotoma (Pallas), M. coccinea 

 (Ellis and Solander), M. khmzingeri Kiikth., M. sanguinea Kiikth., M. zimmeri Kiikth. -, and 

 the new species described beyond. 



1. Mopsella clavigera Ridley. 



Mopsella clavigera Ridley. Zoological Collections H. M. S. Alert, 1884, p. 360. 



Stat. 53. Bay of Nangamessi, Sumba. Up to 36 meters. Coral sand. Near the shore, mud. 



A fragmentary specimen from this station shows the strongly compressed axis and 

 main stem, and peculiar spicules figured by RIDLEY, 1. c. Plate XXXVIII, fig. a, a', a'", for 

 M. clavigera. The specimen is dry and nearly all of the branches are missing. The internodes 

 are pinkish and the nodes crimson. The calyces and polyps can not be satisfactorily studied. 



Spicules. The spicules are exceedingly various in form, but those figured by RIDLEY 

 are quite characteristic. There are numerous clubs with comparatively smooth surfaces, and 

 others flattened and longitudinally grooved, forming figures like two or three extended fingers 

 flattened and closely pressed together. Many also are like irregular potatoes in form, with 

 rounded swellings unlike other verrucse, and sometimes thorny points. Regular tuberculate 

 spindles with the verrucee in symmetrical whorls are also found. 



Color. The colony is dull red and the axis has pink internodes and crimson nodes. 



General distribution. The type locality of this species is in the Indian Ocean. 



2. Mopsella studeri new species. (Plate IX, figs. 410-, Plate XII, fig. 6). 



Stat. 71. Makassar and surroundings. Up to 32 meters. Mud, sand with mud, coral. 



Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands (Pearl Banks). 13 meters. 



(Type locality). 

 Stat. 274. 528'.2S., I3453'-9E. 57 meters. Sand and shells. Stones. 



Colony flabellate and reticulate, 25.3 cm. high and with a spread of 11.5 cm. Two 

 main stems are coherent at base, forming a common stock 1.5 cm. X i cm. in diameter. 

 These separate about 2 cm. from the base, but are reunited by a single anastomosis of the 

 branches. Stem and branches laterally compressed, the larger stem having a cross section of 

 9 mm. X 7 mm. In the lower part of the main stem the nodes blend with the internodes so 

 as to make it difficult to ascertain their limits on superficial examination, but the nodes are 

 evidently much longer than the internodes. On the branches and twigs this relation is reversed, 

 the internodes being much the longer. Some of the distal nodes are but 2 mm. long, while 

 adjacent internodes are 1 1 mm. long. The branching is dichotomous in general, but sometimes 

 lateral and alternate. The furcations are usually U-shaped. Some of the main branches are 

 much compressed, one having a section of 3.8 mm. X 2 mm. The ultimate twigs are nearly 

 round and average about i mm. in diameter, the calyces are very thickly emplanted on three 

 sides of the stem and main branches and on all sides of the smaller branches and twigs. 



SIBOGA-FXPEDITIE XIII* s . 7 



