174 T.OWER INVERTEBRATES. 



side, while, viewed from above, some have a more or less bottle-shaped outline, and 

 others are triangular. P. viiranda has been dredged in the Florida Straits, and near 

 the Shetland Islands. 



P. curinata is a large species with a rather stont test and a bottle-shaped form. It 

 IS about four inches long, of a light claret color with whitish pink spines, and is 

 a native of deep water, as it was dredged at from sixteen himdred to two thousand two 

 hundred and twenty-tive fathoms in the Antarctic Ocean. P. ceratopyga is remarkable 

 for the great width of the .anterior extremity and the narrowness of the anal snout, 

 giving to the test a triangular shape. Viewed laterally and in the rear, the posterior 

 ]irojection has considerable resemblance to the head of a turtle. It occurs in the same 

 localities with the preceding species, and, judging from fragments of some large speci- 

 mens, must attain a length of about seven inches. P. hispida has a very short anal 

 snout, and the shape, viewed from above, is that of a short, broad bottle. The trans- 

 verse section is rounded, instead of obtusely triangular, as in the last species. P. 

 lagancxda and P.phkde are both bottle-shajicd species, more or less circular in transverse 

 section. The former occurs both north and south of the equator, from three hundred 

 and forty-five to two thousand nine hundred fathoms, while the latter, which is a pecu- 

 liarly slender and small species, was found in t)2° '2Ct south latitude, has an extremely 

 thin test, and is of a light yellowish pink color. A peculiar form related to Poiirta- 

 lesia is Spatcmgoa/stis chaUengeri, in which the anal snout is a small projection at the 

 j)osterior end of a sharp keel which runs along the under side from the mouth back- 

 wards. In Echinocrepis cimeata, the general outline, whether viewed from above, 

 laterally, or endwise, approaches a triangle, and there is no anal snout, the anal system 

 .•i]ipearing on the lower or actinal surface. The two last forms were both taken in 

 deep water in the southei-n ocean. Other southern Potirtalesice without an anal snout 

 are Urechimcs naresianus and C'gsiechinus, of which two species, vesica and rryviUn, 

 are known. C. vesica is the only spatangoid thus far known, which can evidently 

 expand and contract its test. CystecJiinus is elliptical in plan and irregularly ti-ian- 

 gular in profile. 



Ccdynere has simple ambulacral pores ; two of the ovaries are in the trivium, and 

 the others are not developed. Its outline is elliptical, and there is a slight keel on 

 the under surface. C. relicta has been taken at Tristan d'Acunha, and near Fayal, in 

 two thousand six hundred and fifty fathoms. The central portion of the oral surface, 

 and the apical surface near the posterior pole, has groups of paddle-shaped spines. 



To the Ananchytinfe belong, besides many fossil forms, a few recent genera, among 

 which ITomolampas has very rudimentary petaloid ambulacra, a flattened test, and a 

 well-developed sub-anal fascicle. IT. fuha is about four inches long, of a light straw 

 color, and heart-like in shape. Large curved spines are scattered at intervals among 

 the short ones that cover the test. It was dredged in two thousand four hundred and 

 twenty-five fathoms, by the 'Challenger' expedition. 



To the Sjiatanginre belong the typical Spatangus^ species of which are common in 

 Europe, and the nearly allied Maretia and Lovenia. Lovenia cordiformis is elongate, 

 heart-shaped, flat upon the oral surface, and provided with numerous very long prim- 

 ary spines, half as long as the test. It occurs on the west coast of Mexico and in Cali- 

 fornia as far north as Point Conception. Here also belongs the fine sjiecies Bveynia 

 aitstralasio', which attains a length of four inches and a width of more than three, and 

 is found in China, Australia, and .Ja|)an, and also PJchinocardium cordatmn of both 

 coasts of the Atlantic. 



