710 THE yOYAGE OF H.M.S. CHALLENGEE. 



Subgenus 2. Phortolarcus, Haeckel. 



Definition. — Lattice-work of the iiTegular cortical shell complete, without large 

 openings or gates. 



3. Phorticium deforme, n. sp. 



Cortical shell irregular, roundish or longish, three times as large as the enclosed subregular, 

 lentelliptical Za7-naciUa-shell, connected with it by two opposite latticed wings (the halves of the 

 transverse girdle of Tetrapyle). Network of the cortical shell irregular, dense, perfectly closed, 

 without larger openings or gates. Surface thorny. (May be regarded as a monstrous form of 

 Larnacalins.) 



Dimensions. — Diameter of the irregular cortical shell 0'15 to 018, of the medidlary shell 0-04 

 to 0-06. 



Habitat. — Pacific, central area, Station 272, depth 2600 fatlioms. 



4. Phorticium ahnorme, n. sp. 



Cortical shell irregular, roundish, tuberous, with five to ten quite irregular or nearly hemi- 

 spherical protuberances, which i-esemble the cupolas of Zonarida. The regular lentelliptical 

 Za?7!«ct7/a-shell is one-third to one-fourth as large as the enclosing cortical shell, and is connected 

 with it by some irregular radial beams. Lattice-work completely closed, without gates. Surface 

 spiny. (May be regarded as an anomalous form of Zoniditnn; as in the other species of this variable 

 genus, the incUviduals are very unequal.) 



Dimensions. — ^Diameter of the irregular cortical shell 0'12 to 0'2, of the medullary shell O'O:^ 

 to 0-05. 



Habitat. — Atlantic and Pacific, tropical zone, surface, and at vai'ious depths. 



Genus 314. Spongophortis,'^ Haeckel, 1881, Proclromus, p. 464. 



Definition. — Phorticicla with irregular cortical shell of spongy framework, 

 enclosing a lentelliptical Xar^^ac^7Za-shapecl medullary shell. 



The genus Spongophortis diifers from' Phorticium in the spongy framework of 

 the cortical shell. This encloses the inner Xa?'?!oci7^rt -shaped medullary shell either 

 du-ectly, or both sheUs are separated by a hoUow interval, and connected either by radial 

 beams or by latticed lamellae. Perhaps both these subgenera might be better separated 

 as genera. 



1 Spongophortis=S'pongy vessel ; (rTriyyo;, (poor's. 



