554 THE VOYAGE OF H.M.S. CHALLENGES. 



the outlines of the spire very different, and the apes (which, as in the case of these two species, is 

 mamillate, and distinct from the acute form of Bittium rcticulatum, Da Costa) is more oblique than 

 it is in these. 



The last four species, Bittium cylindricum, Bittium abruptum, Bittium dclicatum, and Bittium 

 acdonium, I keep here together. They have undeniably the deep oblique siphonal cut on the base 

 toward the point of the pillar, which is a very marked feature in Ceritliiopsis ; but the form of the 

 canal is very variable in all the group, and the elongated and sculptured apex, which is a still 

 more characteristic feature of Ceritliiopsis, is wanting ; and thus, in the absence of the animal and 

 operculum, I prefer classing them as above with Bittium. I confess, however, that on both 

 of these grounds Ccrithiopsis costidata, Moller, seems quite as doubtfully entitled to rank as a 

 Ceritliiopsis. There are others, too, which have gone before, that will probably in the end claim a 

 Ceritliiopsis relationship, but in the absence of animal and operculum cannot be confidently classed 

 at all. 



18. Bittium perparvulum, n. sp. (PI. XXXVIII. fig. 3). J 



Station 172. July 22, 1874. Lat. 20° 58' S., long. 175° 9' W. Inside the reef, 

 Tongatabu. 18 fathoms. Coral mud. 



September 7, 1874. Torres Strait. 7 fathoms. 



September 8, 1874. Flinders Passage, Cape York, North-east Australia. 7 

 fathoms. 



Station 186. September 8, 1874. Lat. 10° 30' S., long. 142° 18' E. "Wednesday 

 Island, Cape York. 8 fathoms. Coral mud. 



July 1875. Eeefs off Honolulu. 40 fathoms. 



Shell. — Very small, obovate to broadly elongate, and conical, pointed, pale chestnut to 

 white, reticulated, with a small conical tip, convex whorls, an impressed suture, a short 

 rounded and slightly conical base, and a small oval mouth. Sculpture : Longitudinals — 

 there are on the last whorl about 14 rather feebly raised ribs, which are strongest at the 

 suture and die out on the base ; these do not appear on the first two regular whorls. 

 Spirals — there are on the last whorl about eight slightly tubercled threads, of which the third 

 faintly angulates the periphery, and the last is near the pillar ; on the earliest whorls 

 there are two, on the later three of these threads. Colour a ruddyish yellow or very pale 

 chestnut, becoming nearly white on the last whorl, but sometimes dark chestnut or white 

 throughout. There is a minute linear stain on the pillar lip. Spire high, and rather 

 narrow, conical, with very slightly convex profile lines. Apex consists of 2 small coni- 

 cally globose whorls, which are smooth and rounded ; the minute tip is barely but dis- 

 tinctly raised. Wlwrls 7 to 9 in all, small, short, faintly keeled, subshouldered, rounded : 

 the last is a little enlarged, and has a rounded very slightly produced base. Suture 

 oblique, impressed, and wide from the contraction of the whorls above and below. Mouth 

 small, oval, diagonally pointed, being slightly angulated above and markedly so at the 



