470 COLLECTIONS FROM MELANESIA. 



103. Stelletta, sp. 



Some fragments of a large specimen which has grown over 

 some coils of Vermetus, not sufficiently complete to he safely 

 described in full. The stellates are minute, and resemble those of 

 S. purpurea and clavosa, but the arms are somewhat stouter and are 

 not provided with heads. 



Hah. Torres Straits, 5-7 fms. 



STELLETTINOPSIS. 



Carter, Ann. 8f Mag. N. II. 1879, iii. p. 348. 



This genus resembles Tethyopsis, Stewart, in that the two typical 

 species have a minute bacillar llesh-spicule just such as that of the 

 new species of Tethyopsis described below ; and if it be, as seems 

 probable, a tetractinellid which has undergone abortion of two arms 

 (as in Placina monolopha, Schulze) of the main spicule, it resembles 

 Tethyopsis further in this tendency to lose the arms of its skeleton- 

 spicule (see description of Tethyopsis dissimilis, supra). Reduction 

 of the triradiate of the latter species by loss of a single arm would 

 make the spiculation (apart from the skeleton-arrangement) essen- 

 tially that of SteMettinopsis, if the bacillar spicule is regarded as 

 an elongate stellate. The new species is assigned here to SteUetti- 

 nopsis because it differs only from the typical species in the absence 

 of the bacillar, — not a point of great importance, if the variation 

 in Geodia as to presence and absence of one or other of the minute 

 spicules is considered. 



I dedicate this new species to Mr. H. J. Carter, to whom is due 

 the credit of establishing this genus, and to whom I owe a great 

 debt in his constant and ready help. 



104. Stellettinopsis carteri. (Plate XLIII. figs, n, n.) 



Pedicellate, on a short cylindrical stalk, passing gradually into 

 a massive, somewhat flattened upper portion, which shows semi- 

 detached lobes. Surface of upper portion dimpled and corrugated 

 (somewhat like the Mammalian cerebrum). No visible vents. Tex- 

 ture in spirit soft, but elastic ; colour in spirit dirty white. Sur- 

 face between the undulations even, but minutely rough. Sarcode 

 continuous, without many cavities ; soft, very pale yellow in colour. 

 Main and dermal skeletons consisting of a confused interlacement 

 of the skeleton acerate spicules, not aggregated into fibres or tracts. 



Spicules: — (1) Skeleton acerate, tapering to sharp points from 

 near the middle; size 1-0 by -02 millim. (2) Stellate, with very 

 slight body, and five to ten straight blunt arms of uniform dia- 

 meter (about -0017 millim.) throughout ; microspined with fine sharp 

 points, which are most prominent at the tips ; size "05 millim. 

 across arms. 



Hah. Prince of Wales Channel, Torres Straits, 5-7 fms. ; bottom 

 sand and shells. 



