Iinl'mn StolLeJ luirnacles. IU)5 



\ ar. invest iijii to r'is. 



DiflVrs from tlio typical form in tlic folli.\vin«j rliaraotcrs 

 only : — The capitulum is relatively narrower and the j)e{lunclc 

 stouter ; the scutal margin of the tcrgum is more nearly 

 strai;;ht, the whole plate being triangular, witii only a 

 notch in the base ; the inframedian latus is reduced to a 

 rudiment or altogether sui)i)ressed. Only the upper latu-i, 

 the tergum, and the lateral part of the scutum are imper- 

 fectly ealeilied. The jjroportions of peduncle and capitulum 

 arc more variable than in typical sj)ecimens. 



This interesting form practically breaks down tlie separation 

 between the sections of the genus with impeifectly and with 

 ])crfcctly developed valves; but I cannot rt gard it as more 

 than a variety of S. laccndivicum, tlie structure of the 

 aj)pcndagcs ^c. of tiie two forms being i entical and tlij 

 general external similarities very close. We liave six 

 specimens of the variety^ all taken in the Laccadive Sea at a 

 depth of 1154 fathoms, on two living Dentalium shells, 

 together with the types of the species. The capitulum of the 

 largest is 11 mm. long and has several dwarf males attached 

 to it. 



(L) Furms with fulli/ cakijied valves and a siviph/ huicel carina. 



Scalpelltan bengahnse, sp. n. 



Capituhim narrow and elongated, almost quadrangular, 

 laterally eoini)ressed, with 15 slightly separated, fully calcified 

 ])lates, which arc conspicuously striated, covered by a very 

 tine, transparent, yellowish, hairless membrane, and have the 

 lines of growth well marked externally. Carina almost 

 straight; umbo terminal, in contact with the carinal n)aigin 

 of the terga; dorsal surface convex, without borders; sides 

 narrow, with dorsal ridges, in contact or almost in contact 

 with otlu r j)Iatcs throughout. Ttrga large, rhomboidal ; 

 iiuibo terminal, not retrovertcd ; oecludent margin straight, 

 vertical ; carinal margin angular, the apex of the angle 

 opposite the umbo of the carina, b(jth parts straight or 

 nearly straight. Scuta almost ))cntagonal, rather small; 

 oecludent margin straight, in a line with that of the terga, 

 but Mith the extreme edge bent in slightly towards the 

 aiiertnrc. Upp<r fati/s large, (|uadrilateral. Rostral and 

 carinal latcra small, sulxMiual, triangular, not reaching the 

 edge of the capitulum. Inframedian tatiis larger, rcgulaily 

 lozcnge-shapecl. Rostral large, subrhomboidal, Avith the 



