20 HOLASCUS. 



The collection contains representatives of the following families: — - Euplec- 

 tellidae, Caulophacidae, Rossellidae, Euretidae, Coscinoporidae, and Treto- 

 calycidae. 



EUPLECTELLIDAE (Gray) Ijima. 



Tubular, cup-shaped or massive Hexasterophora attached by a stalk or a 

 tuft of basal spicules or sedent. Generally with numerous separate oscules. 

 The dermal skeleton is composed of hexactines, the proximal ray of which is the 

 longest. Without hypodermal pentactines. 



The collection comprises four more or less complete specimens and six frag- 

 ments of specimens of Euplectellidae. 



Ijima 1 and F. E. Schulze- distinguish two subfamilies, Euplectellinae and 

 Corbitellinae. The collection contains representatives of the former. 



Euplectellinae Ijima. 



Euplectellidae which are attached by a tuft of basal spicules. 



The collection comprises four more or less complete specimens and six 

 fragments of Euplectellinae. These belong to the two genera, Holascus and 

 Holascella. The latter is new. 



HOLASCUS F. E. Schulze. 



Tubular Euplectellidae (Euplectellinae) with terminal sieve-plate, with 

 root-tuft, and without parietal apertures in the body-wall. The chief support 

 of the body-wall is a network composed of large tetractines, pentactines, or 

 hexactines, held together by slender comitals. Oxyhexasters and graphiocomes 

 are always present. Discohexasters and floricomes are absent. Hexactines 

 with equal rays, calicocomes, and sigms occur in some species and are absent in 

 others. The hypodermals are hexactines with short and thick, spiny distal ray, 

 to which slender comital rhabds are attached. The anchoring spicules of the 

 root-tuft are diactine rhabds with oblique backwardly directed spines and a 

 distal tyle, from which anchor teeth-like spines arise. The morphological 

 centre (axial cross) of these spicules is situated a considerable distance above 

 their terminal anchor-tyle. 



The collection contains two more or less complete specimens and two 

 fragments of this genus. All belong to the same species, which is new. 



' /. Ijima. Studies on the Hexactinellida. III. Journ. Coll. soi. Tokyo, 1903, 18, p. 26, 27. 

 - F. E. Schulze. Loc. cit., p. 173. 



